diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/descriptors/WrappedDescriptors.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/descriptors/WrappedDescriptors.kt
index 47507875c56..90692d8651c 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/descriptors/WrappedDescriptors.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/descriptors/WrappedDescriptors.kt
@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptorImpl
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.descriptors.impl.ReceiverParameterDescriptorImpl
+import org.jetbrains.kotlin.descriptors.impl.TypeAliasConstructorDescriptor
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.descriptors.IrBasedDeclarationDescriptor
@@ -340,7 +341,8 @@ open class WrappedVariableDescriptor(
     }
 }
 
-open class WrappedVariableDescriptorWithAccessor() : VariableDescriptorWithAccessors, WrappedCallableDescriptor<IrLocalDelegatedProperty>(Annotations.EMPTY, SourceElement.NO_SOURCE) {
+open class WrappedVariableDescriptorWithAccessor() : VariableDescriptorWithAccessors,
+    WrappedCallableDescriptor<IrLocalDelegatedProperty>(Annotations.EMPTY, SourceElement.NO_SOURCE) {
     override fun getName(): Name = owner.name
 
     override fun substitute(substitutor: TypeSubstitutor): VariableDescriptor {
@@ -661,7 +663,6 @@ class LazyTypeConstructor(
 
     override val supertypeLoopChecker: SupertypeLoopChecker
         get() = SupertypeLoopChecker.EMPTY
-
 }
 
 open class WrappedEnumEntryDescriptor(
@@ -891,6 +892,62 @@ class WrappedPropertySetterDescriptor(annotations: Annotations, sourceElement: S
     override fun getOriginal(): WrappedPropertySetterDescriptor = this
 }
 
+open class WrappedTypeAliasDescriptor(
+    annotations: Annotations = Annotations.EMPTY,
+    private val sourceElement: SourceElement = SourceElement.NO_SOURCE
+) : WrappedDeclarationDescriptor<IrTypeAlias>(annotations), TypeAliasDescriptor {
+
+    override val underlyingType: SimpleType
+        get() = throw UnsupportedOperationException("Unexpected use of WrappedTypeAliasDescriptor $this")
+
+    override val constructors: Collection<TypeAliasConstructorDescriptor>
+        get() = throw UnsupportedOperationException("Unexpected use of WrappedTypeAliasDescriptor $this")
+
+    override fun substitute(substitutor: TypeSubstitutor): ClassifierDescriptorWithTypeParameters =
+        throw UnsupportedOperationException("Wrapped descriptors should not be substituted")
+
+    override fun getDefaultType(): SimpleType =
+        throw UnsupportedOperationException("Unexpected use of WrappedTypeAliasDescriptor $this")
+
+    override fun getTypeConstructor(): TypeConstructor =
+        throw UnsupportedOperationException("Unexpected use of WrappedTypeAliasDescriptor $this")
+
+    override val expandedType: SimpleType
+        get() = owner.expandedType.toKotlinType() as SimpleType
+
+    override val classDescriptor: ClassDescriptor?
+        get() = expandedType.constructor.declarationDescriptor as ClassDescriptor?
+
+    override fun getOriginal(): TypeAliasDescriptor = this
+
+    override fun isInner(): Boolean = false
+
+    override fun getDeclaredTypeParameters(): List<TypeParameterDescriptor> = owner.typeParameters.map { it.descriptor }
+
+    override fun getContainingDeclaration(): DeclarationDescriptor = getContainingDeclaration(owner)
+
+    override fun getName(): Name = owner.name
+
+    override fun getModality(): Modality = Modality.FINAL
+
+    override fun getSource(): SourceElement = sourceElement
+
+    override fun getVisibility(): Visibility = owner.visibility
+
+    override fun isExpect(): Boolean = false
+
+    override fun isActual(): Boolean = owner.isActual
+
+    override fun isExternal(): Boolean = false
+
+    override fun <R : Any?, D : Any?> accept(visitor: DeclarationDescriptorVisitor<R, D>, data: D): R =
+        visitor.visitTypeAliasDescriptor(this, data)
+
+    override fun acceptVoid(visitor: DeclarationDescriptorVisitor<Void, Void>) {
+        visitor.visitTypeAliasDescriptor(this, null)
+    }
+}
+
 open class WrappedFieldDescriptor(
     annotations: Annotations = Annotations.EMPTY,
     private val sourceElement: SourceElement = SourceElement.NO_SOURCE
diff --git a/compiler/ir/backend.js/src/js.proto b/compiler/ir/backend.js/src/js.proto
index e31a3cce3db..b307fb32063 100644
--- a/compiler/ir/backend.js/src/js.proto
+++ b/compiler/ir/backend.js/src/js.proto
@@ -110,6 +110,11 @@ extend org.jetbrains.kotlin.metadata.PackageFragment {
   optional Files package_fragment_files = 130;
 }
 
+extend org.jetbrains.kotlin.metadata.TypeAlias {
+  // TODO repeated org.jetbrains.kotlin.metadata.Annotation type_alias_annotation = 130;
+  optional DescriptorUniqId type_alias_uniq_id = 131;
+}
+
 message Classes {
   // id in StringTable
   repeated int32 class_name = 1 [packed = true];
diff --git a/compiler/ir/serialization.common/src/KotlinIr.proto b/compiler/ir/serialization.common/src/KotlinIr.proto
index 45ad45cb727..4766f0c1ed9 100644
--- a/compiler/ir/serialization.common/src/KotlinIr.proto
+++ b/compiler/ir/serialization.common/src/KotlinIr.proto
@@ -127,6 +127,7 @@ enum IrSymbolKind {
   RECEIVER_PARAMETER_SYMBOL = 12; // ReceiverParameterDescriptor rather than ValueParameterDescriptor.
   PROPERTY_SYMBOL = 13;
   LOCAL_DELEGATED_PROPERTY_SYMBOL = 14;
+  TYPEALIAS_SYMBOL = 15;
 }
 
 message IrSymbolData {
@@ -182,6 +183,14 @@ message IrSimpleType {
   required IrSymbol classifier = 2;
   required bool has_question_mark = 3;
   repeated IrTypeArgument argument = 4;
+  optional IrTypeAbbreviation abbreviation = 5;
+}
+
+message IrTypeAbbreviation {
+  required Annotations annotations = 1;
+  required IrSymbol type_alias = 2;
+  required bool has_question_mark = 3;
+  repeated IrTypeArgument argument = 4;
 }
 
 message IrDynamicType {
@@ -669,6 +678,15 @@ message IrClass {
   repeated IrTypeIndex super_type = 14;
 }
 
+message IrTypeAlias {
+  required IrDeclarationBase base = 1;
+  required String name = 2;
+  required Visibility visibility = 3;
+  required IrTypeParameterContainer type_parameters = 4;
+  required IrTypeIndex expanded_type = 5;
+  required bool is_actual = 6;
+}
+
 message IrEnumEntry {
   required IrDeclarationBase base = 1;
   optional IrExpression initializer = 2;
@@ -697,6 +715,7 @@ message IrDeclaration {
     IrVariable ir_variable = 9;
     IrValueParameter ir_value_parameter = 10;
     IrLocalDelegatedProperty ir_local_delegated_property = 11;
+    IrTypeAlias ir_type_alias = 12;
   }
 }
 
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleDeserializer.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleDeserializer.kt
index e73cfb050ed..b158e0093f2 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleDeserializer.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleDeserializer.kt
@@ -31,10 +31,7 @@ import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.symbols.impl.IrTypeParameterSymbolImpl
-import org.jetbrains.kotlin.ir.types.IrDynamicType
-import org.jetbrains.kotlin.ir.types.IrErrorType
-import org.jetbrains.kotlin.ir.types.IrSimpleType
-import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.types.impl.*
 import org.jetbrains.kotlin.ir.util.SymbolTable
 import org.jetbrains.kotlin.ir.util.render
@@ -100,6 +97,8 @@ import org.jetbrains.kotlin.backend.common.serialization.proto.IrSyntheticBodyKi
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrThrow as ProtoThrow
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrTry as ProtoTry
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrType as ProtoType
+import org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation as ProtoTypeAbbreviation
+import org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias as ProtoTypeAlias
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument as ProtoTypeArgument
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex as ProtoTypeIndex
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeOp as ProtoTypeOp
@@ -191,7 +190,8 @@ abstract class IrModuleDeserializer(
                 symbol,
                 proto.hasQuestionMark,
                 arguments,
-                annotations
+                annotations,
+                if (proto.hasAbbreviation()) deserializeTypeAbbreviation(proto.abbreviation) else null
             )
         }
         logger.log { "ir_type = $result; render = ${result.render()}" }
@@ -199,6 +199,17 @@ abstract class IrModuleDeserializer(
 
     }
 
+    fun deserializeTypeAbbreviation(proto: ProtoTypeAbbreviation): IrTypeAbbreviation =
+        IrTypeAbbreviationImpl(
+            deserializeIrSymbol(proto.typeAlias).let {
+                it as? IrTypeAliasSymbol
+                    ?: error("IrTypeAliasSymbol expected: $it")
+            },
+            proto.hasQuestionMark,
+            proto.argumentList.map { deserializeIrTypeArgument(it) },
+            deserializeAnnotations(proto.annotations)
+        )
+
     fun deserializeDynamicType(proto: ProtoDynamicType): IrDynamicType {
         val annotations = deserializeAnnotations(proto.annotations)
         return IrDynamicTypeImpl(null, annotations, Variance.INVARIANT)
@@ -981,6 +992,27 @@ abstract class IrModuleDeserializer(
             }
         }
 
+    private fun deserializeIrTypeAlias(proto: ProtoTypeAlias) =
+        withDeserializedIrDeclarationBase(proto.base) { symbol, startOffset, endOffset, origin ->
+            symbolTable.declareTypeAlias((symbol as IrTypeAliasSymbol).descriptor) {
+                IrTypeAliasImpl(
+                    startOffset, endOffset,
+                    it,
+                    deserializeName(proto.name),
+                    deserializeVisibility(proto.visibility),
+                    deserializeIrType(proto.expandedType),
+                    proto.isActual,
+                    origin
+                )
+            }.usingParent {
+                proto.typeParameters.typeParameterList.mapTo(typeParameters) {
+                    deserializeIrTypeParameter(it)
+                }
+
+                (descriptor as? WrappedTypeAliasDescriptor)?.bind(this)
+            }
+        }
+
     private inline fun <T : IrFunction> withDeserializedIrFunctionBase(
         proto: ProtoFunctionBase,
         block: (IrFunctionSymbol, Int, Int, IrDeclarationOrigin) -> T
@@ -1232,30 +1264,19 @@ abstract class IrModuleDeserializer(
 
     private fun deserializeDeclaration(proto: ProtoDeclaration): IrDeclaration {
         val declaration: IrDeclaration = when (proto.declaratorCase!!) {
-            IR_ANONYMOUS_INIT
-            -> deserializeIrAnonymousInit(proto.irAnonymousInit)
-            IR_CONSTRUCTOR
-            -> deserializeIrConstructor(proto.irConstructor)
-            IR_FIELD
-            -> deserializeIrField(proto.irField)
-            IR_CLASS
-            -> deserializeIrClass(proto.irClass)
-            IR_FUNCTION
-            -> deserializeIrFunction(proto.irFunction)
-            IR_PROPERTY
-            -> deserializeIrProperty(proto.irProperty)
-            IR_TYPE_PARAMETER
-            -> deserializeIrTypeParameter(proto.irTypeParameter)
-            IR_VARIABLE
-            -> deserializeIrVariable(proto.irVariable)
-            IR_VALUE_PARAMETER
-            -> deserializeIrValueParameter(proto.irValueParameter)
-            IR_ENUM_ENTRY
-            -> deserializeIrEnumEntry(proto.irEnumEntry)
-            IR_LOCAL_DELEGATED_PROPERTY
-            -> deserializeIrLocalDelegatedProperty(proto.irLocalDelegatedProperty)
-            DECLARATOR_NOT_SET
-            -> error("Declaration deserialization not implemented: ${proto.declaratorCase}")
+            IR_ANONYMOUS_INIT -> deserializeIrAnonymousInit(proto.irAnonymousInit)
+            IR_CONSTRUCTOR -> deserializeIrConstructor(proto.irConstructor)
+            IR_FIELD -> deserializeIrField(proto.irField)
+            IR_CLASS -> deserializeIrClass(proto.irClass)
+            IR_FUNCTION -> deserializeIrFunction(proto.irFunction)
+            IR_PROPERTY -> deserializeIrProperty(proto.irProperty)
+            IR_TYPE_PARAMETER -> deserializeIrTypeParameter(proto.irTypeParameter)
+            IR_VARIABLE -> deserializeIrVariable(proto.irVariable)
+            IR_VALUE_PARAMETER -> deserializeIrValueParameter(proto.irValueParameter)
+            IR_ENUM_ENTRY -> deserializeIrEnumEntry(proto.irEnumEntry)
+            IR_LOCAL_DELEGATED_PROPERTY -> deserializeIrLocalDelegatedProperty(proto.irLocalDelegatedProperty)
+            IR_TYPE_ALIAS -> deserializeIrTypeAlias(proto.irTypeAlias)
+            DECLARATOR_NOT_SET -> error("Declaration deserialization not implemented: ${proto.declaratorCase}")
         }
 
         logger.log { "### Deserialized declaration: ${declaration.descriptor} -> ${ir2string(declaration)}" }
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleSerializer.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleSerializer.kt
index e5b2c893b2d..1ff09f92dd1 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleSerializer.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleSerializer.kt
@@ -61,8 +61,8 @@ import org.jetbrains.kotlin.backend.common.serialization.proto.IrEnumConstructor
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrEnumEntry as ProtoEnumEntry
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrErrorType as ProtoErrorType
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrExpression as ProtoExpression
-import org.jetbrains.kotlin.backend.common.serialization.proto.IrFile as ProtoFile
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrField as ProtoField
+import org.jetbrains.kotlin.backend.common.serialization.proto.IrFile as ProtoFile
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrFunction as ProtoFunction
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrFunctionBase as ProtoFunctionBase
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrFunctionExpression as ProtoFunctionExpression
@@ -96,6 +96,8 @@ import org.jetbrains.kotlin.backend.common.serialization.proto.IrSyntheticBodyKi
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrThrow as ProtoThrow
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrTry as ProtoTry
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrType as ProtoType
+import org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation as ProtoTypeAbbreviation
+import org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias as ProtoTypeAlias
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument as ProtoTypeArgument
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex as ProtoTypeIndex
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeOp as ProtoTypeOp
@@ -212,6 +214,8 @@ open class IrModuleSerializer(
             ProtoSymbolKind.PROPERTY_SYMBOL
         is IrLocalDelegatedPropertySymbol ->
             ProtoSymbolKind.LOCAL_DELEGATED_PROPERTY_SYMBOL
+        is IrTypeAliasSymbol ->
+            ProtoSymbolKind.TYPEALIAS_SYMBOL
         else ->
             TODO("Unexpected symbol kind: $symbol")
     }
@@ -231,7 +235,7 @@ open class IrModuleSerializer(
             declarationTable.uniqIdByDeclaration((declaration).findTopLevelDeclaration())
         proto.setTopLevelUniqId(protoUniqId(topLevelUniqId))
 
-        descriptorReferenceSerializer.serializeDescriptorReference(declaration) ?. let {
+        descriptorReferenceSerializer.serializeDescriptorReference(declaration)?.let {
             proto.setDescriptorReference(it)
         }
 
@@ -296,12 +300,26 @@ open class IrModuleSerializer(
             .setAnnotations(serializeAnnotations(type.annotations))
             .setClassifier(serializeIrSymbol(type.classifier))
             .setHasQuestionMark(type.hasQuestionMark)
+        type.abbreviation?.let {
+            proto.setAbbreviation(serializeIrTypeAbbreviation(it))
+        }
         type.arguments.forEach {
             proto.addArgument(serializeTypeArgument(it))
         }
         return proto.build()
     }
 
+    private fun serializeIrTypeAbbreviation(typeAbbreviation: IrTypeAbbreviation): ProtoTypeAbbreviation {
+        val proto = ProtoTypeAbbreviation.newBuilder()
+            .setAnnotations(serializeAnnotations(typeAbbreviation.annotations))
+            .setTypeAlias(serializeIrSymbol(typeAbbreviation.typeAlias))
+            .setHasQuestionMark(typeAbbreviation.hasQuestionMark)
+        typeAbbreviation.arguments.forEach {
+            proto.addArgument(serializeTypeArgument(it))
+        }
+        return proto.build()
+    }
+
     fun serializeDynamicType(type: IrDynamicType) = ProtoDynamicType.newBuilder()
         .setAnnotations(serializeAnnotations(type.annotations))
         .build()
@@ -311,7 +329,7 @@ open class IrModuleSerializer(
         .build()
 
     private fun serializeIrTypeData(type: IrType): ProtoType {
-        logger.log { "### serializing IrType: " + type }
+        logger.log { "### serializing IrType: $type" }
         val proto = ProtoType.newBuilder()
         when (type) {
             is IrSimpleType ->
@@ -345,34 +363,36 @@ open class IrModuleSerializer(
         val annotations: List<IrConstructorCall>
     )
 
-    data class IrTypeArgumentKey (
+    data class IrTypeArgumentKey(
         val kind: IrTypeArgumentKind,
         val variance: Variance?,
         val type: IrTypeKey?
     )
 
-    val IrType.toIrTypeKey: IrTypeKey get() = IrTypeKey(
-        kind = when (this) {
-            is IrSimpleType -> IrTypeKind.SIMPLE
-            is IrDynamicType -> IrTypeKind.DYNAMIC
-            is IrErrorType -> IrTypeKind.ERROR
-            else -> error("Unexpected IrType kind: $this")
-        },
-        classifier = this.classifierOrNull,
-        hasQuestionMark = (this as? IrSimpleType)?.hasQuestionMark,
-        arguments = (this as? IrSimpleType)?.arguments?.map { it.toIrTypeArgumentKey },
-        annotations = this.annotations
-    )
+    val IrType.toIrTypeKey: IrTypeKey
+        get() = IrTypeKey(
+            kind = when (this) {
+                is IrSimpleType -> IrTypeKind.SIMPLE
+                is IrDynamicType -> IrTypeKind.DYNAMIC
+                is IrErrorType -> IrTypeKind.ERROR
+                else -> error("Unexpected IrType kind: $this")
+            },
+            classifier = this.classifierOrNull,
+            hasQuestionMark = (this as? IrSimpleType)?.hasQuestionMark,
+            arguments = (this as? IrSimpleType)?.arguments?.map { it.toIrTypeArgumentKey },
+            annotations = this.annotations
+        )
 
-    val IrTypeArgument.toIrTypeArgumentKey: IrTypeArgumentKey get() = IrTypeArgumentKey(
-        kind = when (this) {
-            is IrStarProjection -> IrTypeArgumentKind.STAR
-            is IrTypeProjection -> IrTypeArgumentKind.PROJECTION
-            else -> error("Unexpected type argument kind: $this")
-        },
-        variance = (this as? IrTypeProjection)?.variance,
-        type = (this as? IrTypeProjection)?.type?.toIrTypeKey
-    )
+    val IrTypeArgument.toIrTypeArgumentKey: IrTypeArgumentKey
+        get() = IrTypeArgumentKey(
+            kind = when (this) {
+                is IrStarProjection -> IrTypeArgumentKind.STAR
+                is IrTypeProjection -> IrTypeArgumentKind.PROJECTION
+                else -> error("Unexpected type argument kind: $this")
+            },
+            variance = (this as? IrTypeProjection)?.variance,
+            type = (this as? IrTypeProjection)?.type?.toIrTypeKey
+        )
 
     fun serializeIrType(type: IrType): ProtoTypeIndex {
         val proto = ProtoTypeIndex.newBuilder()
@@ -633,7 +653,7 @@ open class IrModuleSerializer(
         ProtoSetField.newBuilder()
             .setFieldAccess(serializeFieldAccessCommon(expression))
             .setValue(serializeExpression(expression.value)).apply {
-                expression.origin?.let{ setOrigin(serializeIrStatementOrigin(it)) }
+                expression.origin?.let { setOrigin(serializeIrStatementOrigin(it)) }
             }
             .build()
 
@@ -641,7 +661,7 @@ open class IrModuleSerializer(
         ProtoSetVariable.newBuilder()
             .setSymbol(serializeIrSymbol(expression.symbol))
             .setValue(serializeExpression(expression.value)).apply {
-                expression.origin?.let{ setOrigin(serializeIrStatementOrigin(it)) }
+                expression.origin?.let { setOrigin(serializeIrStatementOrigin(it)) }
             }
             .build()
 
@@ -738,7 +758,7 @@ open class IrModuleSerializer(
     private fun serializeWhen(expression: IrWhen): ProtoWhen {
         val proto = ProtoWhen.newBuilder()
 
-        expression.origin?.let{ proto.setOrigin(serializeIrStatementOrigin(it)) }
+        expression.origin?.let { proto.setOrigin(serializeIrStatementOrigin(it)) }
 
         val branches = expression.branches
         branches.forEach {
@@ -751,7 +771,7 @@ open class IrModuleSerializer(
     private fun serializeLoop(expression: IrLoop): ProtoLoop {
         val proto = ProtoLoop.newBuilder()
             .setCondition(serializeExpression(expression.condition)).apply {
-                expression.origin?.let{ setOrigin(serializeIrStatementOrigin(it)) }
+                expression.origin?.let { setOrigin(serializeIrStatementOrigin(it)) }
             }
 
         expression.label?.let {
@@ -1155,6 +1175,16 @@ open class IrModuleSerializer(
         return proto.build()
     }
 
+    private fun serializeIrTypeAlias(typeAlias: IrTypeAlias): ProtoTypeAlias =
+        ProtoTypeAlias.newBuilder()
+            .setBase(serializeIrDeclarationBase(typeAlias))
+            .setName(serializeName(typeAlias.name))
+            .setVisibility(serializeVisibility(typeAlias.visibility))
+            .setTypeParameters(serializeIrTypeParameterContainer(typeAlias.typeParameters))
+            .setExpandedType(serializeIrType(typeAlias.expandedType))
+            .setIsActual(typeAlias.isActual)
+            .build()
+
     private fun serializeIrEnumEntry(enumEntry: IrEnumEntry): ProtoEnumEntry {
         val proto = ProtoEnumEntry.newBuilder()
             .setBase(serializeIrDeclarationBase(enumEntry))
@@ -1197,8 +1227,10 @@ open class IrModuleSerializer(
                 proto.irProperty = serializeIrProperty(declaration)
             is IrLocalDelegatedProperty ->
                 proto.irLocalDelegatedProperty = serializeIrLocalDelegatedProperty(declaration)
-            else
-            -> TODO("Declaration serialization not supported yet: $declaration")
+            is IrTypeAlias ->
+                proto.irTypeAlias = serializeIrTypeAlias(declaration)
+            else ->
+                TODO("Declaration serialization not supported yet: $declaration")
         }
 
         return proto.build()
@@ -1236,13 +1268,13 @@ open class IrModuleSerializer(
 
         // Make sure that all top level properties are initialized on library's load.
         file.declarations
-                .filterIsInstance<IrProperty>()
-                .filter { it.backingField?.initializer != null && !it.isConst }
-                .forEach { proto.addExplicitlyExportedToCompiler(serializeIrSymbol(it.backingField!!.symbol)) }
+            .filterIsInstance<IrProperty>()
+            .filter { it.backingField?.initializer != null && !it.isConst }
+            .forEach { proto.addExplicitlyExportedToCompiler(serializeIrSymbol(it.backingField!!.symbol)) }
 
         // TODO: Konan specific
 
-        file.acceptVoid(object: IrElementVisitorVoid {
+        file.acceptVoid(object : IrElementVisitorVoid {
             override fun visitElement(element: IrElement) {
                 element.acceptChildrenVoid(this)
             }
@@ -1299,9 +1331,11 @@ open class IrModuleSerializer(
 
     fun serializedIrModule(module: IrModuleFragment): SerializedIr {
         val moduleHeader = serializeModule(module).toByteArray()
-        return SerializedIr(moduleHeader, symbolTableWriter.finishWriting().absolutePath,
-                            typeTableWriter.finishWriting().absolutePath,
-                            stringTableWriter.finishWriting().absolutePath,
-                            writer.finishWriting().absolutePath)
+        return SerializedIr(
+            moduleHeader, symbolTableWriter.finishWriting().absolutePath,
+            typeTableWriter.finishWriting().absolutePath,
+            stringTableWriter.finishWriting().absolutePath,
+            writer.finishWriting().absolutePath
+        )
     }
 }
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinIrLinker.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinIrLinker.kt
index 071f20c2a7d..a4300b01200 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinIrLinker.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinIrLinker.kt
@@ -121,6 +121,11 @@ abstract class KotlinIrLinker(
                     descriptor as FunctionDescriptor?
                         ?: WrappedSimpleFunctionDescriptor()
                 )
+            ProtoSymbolKind.TYPEALIAS_SYMBOL ->
+                symbolTable.referenceTypeAlias(
+                    descriptor as TypeAliasDescriptor?
+                        ?: WrappedTypeAliasDescriptor()
+                )
             ProtoSymbolKind.VARIABLE_SYMBOL ->
                 IrVariableSymbolImpl(
                     descriptor as VariableDescriptor?
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinMangler.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinMangler.kt
index 41e1bfca27b..b8edb5e757e 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinMangler.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinMangler.kt
@@ -24,7 +24,7 @@ interface KotlinMangler {
     val IrType.isInlined: Boolean
 }
 
-abstract class KotlinManglerImpl: KotlinMangler {
+abstract class KotlinManglerImpl : KotlinMangler {
     override val String.hashMangle get() = this.cityHash64()
 
     override val IrDeclaration.hashedMangle: Long
@@ -75,6 +75,7 @@ abstract class KotlinManglerImpl: KotlinMangler {
             is IrFunction -> this.visibility
             is IrProperty -> this.visibility
             is IrField -> this.visibility
+            is IrTypeAlias -> this.visibility
             else -> null
         }
 
@@ -144,9 +145,10 @@ abstract class KotlinManglerImpl: KotlinMangler {
     val IrValueParameter.extensionReceiverNamePart: String
         get() = "@${typeToHashString(this.type)}."
 
-    open val IrFunction.argsPart get() = this.valueParameters.map {
-        "${typeToHashString(it.type)}${if (it.isVararg) "_VarArg" else ""}"
-    }.joinToString(";")
+    open val IrFunction.argsPart
+        get() = this.valueParameters.map {
+            "${typeToHashString(it.type)}${if (it.isVararg) "_VarArg" else ""}"
+        }.joinToString(";")
 
     open val IrFunction.signature: String
         get() {
@@ -170,7 +172,7 @@ abstract class KotlinManglerImpl: KotlinMangler {
     override val IrFunction.functionName: String
         get() {
             // TODO: Again. We can't call super in children, so provide a hook for now.
-            this.platformSpecificFunctionName ?. let { return it }
+            this.platformSpecificFunctionName?.let { return it }
             val name = this.name.mangleIfInternal(this.module, this.visibility)
             return "$name$signature"
         }
@@ -211,22 +213,25 @@ abstract class KotlinManglerImpl: KotlinMangler {
             return "ktypeparam:$containingDeclarationPart$name@$index"
         }
 
+    val IrTypeAlias.symbolName: String
+        get() {
+            val containingDeclarationPart = parent.fqNameForIrSerialization.let {
+                if (it.isRoot) "" else "$it."
+            }
+            return "ktypealias:$containingDeclarationPart$name"
+        }
+
 // This is a little extension over what's used in real mangling
 // since some declarations never appear in the bitcode symbols.
 
     internal fun IrDeclaration.uniqSymbolName(): String = when (this) {
-        is IrFunction
-        -> this.uniqFunctionName
-        is IrProperty
-        -> this.symbolName
-        is IrClass
-        -> this.typeInfoSymbolName
-        is IrField
-        -> this.symbolName
-        is IrEnumEntry
-        -> this.symbolName
-        is IrTypeParameter
-        -> this.symbolName
+        is IrFunction -> this.uniqFunctionName
+        is IrProperty -> this.symbolName
+        is IrClass -> this.typeInfoSymbolName
+        is IrField -> this.symbolName
+        is IrEnumEntry -> this.symbolName
+        is IrTypeParameter -> this.symbolName
+        is IrTypeAlias -> this.symbolName
         else -> error("Unexpected exported declaration: $this")
     }
 
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/DescriptorReference.java b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/DescriptorReference.java
index 09f3fd9219f..cf481725a6a 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/DescriptorReference.java
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/DescriptorReference.java
@@ -348,12 +348,20 @@ public final class DescriptorReference extends
   private boolean isTypeParameter_;
   /**
    * <code>optional bool is_type_parameter = 12 [default = false];</code>
+   *
+   * <pre>
+   * TODO optional bool is_type_alias = 13 [default = false];
+   * </pre>
    */
   public boolean hasIsTypeParameter() {
     return ((bitField0_ & 0x00000800) == 0x00000800);
   }
   /**
    * <code>optional bool is_type_parameter = 12 [default = false];</code>
+   *
+   * <pre>
+   * TODO optional bool is_type_alias = 13 [default = false];
+   * </pre>
    */
   public boolean getIsTypeParameter() {
     return isTypeParameter_;
@@ -1265,18 +1273,30 @@ public final class DescriptorReference extends
     private boolean isTypeParameter_ ;
     /**
      * <code>optional bool is_type_parameter = 12 [default = false];</code>
+     *
+     * <pre>
+     * TODO optional bool is_type_alias = 13 [default = false];
+     * </pre>
      */
     public boolean hasIsTypeParameter() {
       return ((bitField0_ & 0x00000800) == 0x00000800);
     }
     /**
      * <code>optional bool is_type_parameter = 12 [default = false];</code>
+     *
+     * <pre>
+     * TODO optional bool is_type_alias = 13 [default = false];
+     * </pre>
      */
     public boolean getIsTypeParameter() {
       return isTypeParameter_;
     }
     /**
      * <code>optional bool is_type_parameter = 12 [default = false];</code>
+     *
+     * <pre>
+     * TODO optional bool is_type_alias = 13 [default = false];
+     * </pre>
      */
     public Builder setIsTypeParameter(boolean value) {
       bitField0_ |= 0x00000800;
@@ -1286,6 +1306,10 @@ public final class DescriptorReference extends
     }
     /**
      * <code>optional bool is_type_parameter = 12 [default = false];</code>
+     *
+     * <pre>
+     * TODO optional bool is_type_alias = 13 [default = false];
+     * </pre>
      */
     public Builder clearIsTypeParameter() {
       bitField0_ = (bitField0_ & ~0x00000800);
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/DescriptorReferenceOrBuilder.java b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/DescriptorReferenceOrBuilder.java
index 6c29103433a..718dea5123b 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/DescriptorReferenceOrBuilder.java
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/DescriptorReferenceOrBuilder.java
@@ -108,10 +108,18 @@ public interface DescriptorReferenceOrBuilder extends
 
   /**
    * <code>optional bool is_type_parameter = 12 [default = false];</code>
+   *
+   * <pre>
+   * TODO optional bool is_type_alias = 13 [default = false];
+   * </pre>
    */
   boolean hasIsTypeParameter();
   /**
    * <code>optional bool is_type_parameter = 12 [default = false];</code>
+   *
+   * <pre>
+   * TODO optional bool is_type_alias = 13 [default = false];
+   * </pre>
    */
   boolean getIsTypeParameter();
 }
\ No newline at end of file
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrDeclaration.java b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrDeclaration.java
index d7dd19880d7..792cfc00968 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrDeclaration.java
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrDeclaration.java
@@ -196,6 +196,19 @@ public final class IrDeclaration extends
             declaratorCase_ = 11;
             break;
           }
+          case 98: {
+            org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias.Builder subBuilder = null;
+            if (declaratorCase_ == 12) {
+              subBuilder = ((org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias) declarator_).toBuilder();
+            }
+            declarator_ = input.readMessage(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias.PARSER, extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom((org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias) declarator_);
+              declarator_ = subBuilder.buildPartial();
+            }
+            declaratorCase_ = 12;
+            break;
+          }
         }
       }
     } catch (org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException e) {
@@ -245,6 +258,7 @@ public final class IrDeclaration extends
     IR_VARIABLE(9),
     IR_VALUE_PARAMETER(10),
     IR_LOCAL_DELEGATED_PROPERTY(11),
+    IR_TYPE_ALIAS(12),
     DECLARATOR_NOT_SET(0);
     private int value = 0;
     private DeclaratorCase(int value) {
@@ -263,6 +277,7 @@ public final class IrDeclaration extends
         case 9: return IR_VARIABLE;
         case 10: return IR_VALUE_PARAMETER;
         case 11: return IR_LOCAL_DELEGATED_PROPERTY;
+        case 12: return IR_TYPE_ALIAS;
         case 0: return DECLARATOR_NOT_SET;
         default: throw new java.lang.IllegalArgumentException(
           "Value is undefined for this oneof enum.");
@@ -466,6 +481,23 @@ public final class IrDeclaration extends
     return org.jetbrains.kotlin.backend.common.serialization.proto.IrLocalDelegatedProperty.getDefaultInstance();
   }
 
+  public static final int IR_TYPE_ALIAS_FIELD_NUMBER = 12;
+  /**
+   * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias ir_type_alias = 12;</code>
+   */
+  public boolean hasIrTypeAlias() {
+    return declaratorCase_ == 12;
+  }
+  /**
+   * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias ir_type_alias = 12;</code>
+   */
+  public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias getIrTypeAlias() {
+    if (declaratorCase_ == 12) {
+       return (org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias) declarator_;
+    }
+    return org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias.getDefaultInstance();
+  }
+
   private void initFields() {
   }
   private byte memoizedIsInitialized = -1;
@@ -540,6 +572,12 @@ public final class IrDeclaration extends
         return false;
       }
     }
+    if (hasIrTypeAlias()) {
+      if (!getIrTypeAlias().isInitialized()) {
+        memoizedIsInitialized = 0;
+        return false;
+      }
+    }
     memoizedIsInitialized = 1;
     return true;
   }
@@ -580,6 +618,9 @@ public final class IrDeclaration extends
     if (declaratorCase_ == 11) {
       output.writeMessage(11, (org.jetbrains.kotlin.backend.common.serialization.proto.IrLocalDelegatedProperty) declarator_);
     }
+    if (declaratorCase_ == 12) {
+      output.writeMessage(12, (org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias) declarator_);
+    }
     output.writeRawBytes(unknownFields);
   }
 
@@ -633,6 +674,10 @@ public final class IrDeclaration extends
       size += org.jetbrains.kotlin.protobuf.CodedOutputStream
         .computeMessageSize(11, (org.jetbrains.kotlin.backend.common.serialization.proto.IrLocalDelegatedProperty) declarator_);
     }
+    if (declaratorCase_ == 12) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeMessageSize(12, (org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias) declarator_);
+    }
     size += unknownFields.size();
     memoizedSerializedSize = size;
     return size;
@@ -785,6 +830,9 @@ public final class IrDeclaration extends
       if (declaratorCase_ == 11) {
         result.declarator_ = declarator_;
       }
+      if (declaratorCase_ == 12) {
+        result.declarator_ = declarator_;
+      }
       result.bitField0_ = to_bitField0_;
       result.declaratorCase_ = declaratorCase_;
       return result;
@@ -837,6 +885,10 @@ public final class IrDeclaration extends
           mergeIrLocalDelegatedProperty(other.getIrLocalDelegatedProperty());
           break;
         }
+        case IR_TYPE_ALIAS: {
+          mergeIrTypeAlias(other.getIrTypeAlias());
+          break;
+        }
         case DECLARATOR_NOT_SET: {
           break;
         }
@@ -913,6 +965,12 @@ public final class IrDeclaration extends
           return false;
         }
       }
+      if (hasIrTypeAlias()) {
+        if (!getIrTypeAlias().isInitialized()) {
+          
+          return false;
+        }
+      }
       return true;
     }
 
@@ -1653,6 +1711,70 @@ public final class IrDeclaration extends
       return this;
     }
 
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias ir_type_alias = 12;</code>
+     */
+    public boolean hasIrTypeAlias() {
+      return declaratorCase_ == 12;
+    }
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias ir_type_alias = 12;</code>
+     */
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias getIrTypeAlias() {
+      if (declaratorCase_ == 12) {
+        return (org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias) declarator_;
+      }
+      return org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias.getDefaultInstance();
+    }
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias ir_type_alias = 12;</code>
+     */
+    public Builder setIrTypeAlias(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      declarator_ = value;
+
+      declaratorCase_ = 12;
+      return this;
+    }
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias ir_type_alias = 12;</code>
+     */
+    public Builder setIrTypeAlias(
+        org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias.Builder builderForValue) {
+      declarator_ = builderForValue.build();
+
+      declaratorCase_ = 12;
+      return this;
+    }
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias ir_type_alias = 12;</code>
+     */
+    public Builder mergeIrTypeAlias(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias value) {
+      if (declaratorCase_ == 12 &&
+          declarator_ != org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias.getDefaultInstance()) {
+        declarator_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias.newBuilder((org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias) declarator_)
+            .mergeFrom(value).buildPartial();
+      } else {
+        declarator_ = value;
+      }
+
+      declaratorCase_ = 12;
+      return this;
+    }
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias ir_type_alias = 12;</code>
+     */
+    public Builder clearIrTypeAlias() {
+      if (declaratorCase_ == 12) {
+        declaratorCase_ = 0;
+        declarator_ = null;
+        
+      }
+      return this;
+    }
+
     // @@protoc_insertion_point(builder_scope:org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclaration)
   }
 
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrDeclarationOrBuilder.java b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrDeclarationOrBuilder.java
index dcca2a36d21..4490d79de89 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrDeclarationOrBuilder.java
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrDeclarationOrBuilder.java
@@ -105,4 +105,13 @@ public interface IrDeclarationOrBuilder extends
    * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrLocalDelegatedProperty ir_local_delegated_property = 11;</code>
    */
   org.jetbrains.kotlin.backend.common.serialization.proto.IrLocalDelegatedProperty getIrLocalDelegatedProperty();
+
+  /**
+   * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias ir_type_alias = 12;</code>
+   */
+  boolean hasIrTypeAlias();
+  /**
+   * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias ir_type_alias = 12;</code>
+   */
+  org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias getIrTypeAlias();
 }
\ No newline at end of file
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSimpleType.java b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSimpleType.java
index 37e1f942548..d8fd59f83db 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSimpleType.java
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSimpleType.java
@@ -92,6 +92,19 @@ public final class IrSimpleType extends
             argument_.add(input.readMessage(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument.PARSER, extensionRegistry));
             break;
           }
+          case 42: {
+            org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.Builder subBuilder = null;
+            if (((bitField0_ & 0x00000008) == 0x00000008)) {
+              subBuilder = abbreviation_.toBuilder();
+            }
+            abbreviation_ = input.readMessage(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.PARSER, extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom(abbreviation_);
+              abbreviation_ = subBuilder.buildPartial();
+            }
+            bitField0_ |= 0x00000008;
+            break;
+          }
         }
       }
     } catch (org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException e) {
@@ -209,11 +222,27 @@ public final class IrSimpleType extends
     return argument_.get(index);
   }
 
+  public static final int ABBREVIATION_FIELD_NUMBER = 5;
+  private org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation_;
+  /**
+   * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation = 5;</code>
+   */
+  public boolean hasAbbreviation() {
+    return ((bitField0_ & 0x00000008) == 0x00000008);
+  }
+  /**
+   * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation = 5;</code>
+   */
+  public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation getAbbreviation() {
+    return abbreviation_;
+  }
+
   private void initFields() {
     annotations_ = org.jetbrains.kotlin.backend.common.serialization.proto.Annotations.getDefaultInstance();
     classifier_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol.getDefaultInstance();
     hasQuestionMark_ = false;
     argument_ = java.util.Collections.emptyList();
+    abbreviation_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.getDefaultInstance();
   }
   private byte memoizedIsInitialized = -1;
   public final boolean isInitialized() {
@@ -247,6 +276,12 @@ public final class IrSimpleType extends
         return false;
       }
     }
+    if (hasAbbreviation()) {
+      if (!getAbbreviation().isInitialized()) {
+        memoizedIsInitialized = 0;
+        return false;
+      }
+    }
     memoizedIsInitialized = 1;
     return true;
   }
@@ -266,6 +301,9 @@ public final class IrSimpleType extends
     for (int i = 0; i < argument_.size(); i++) {
       output.writeMessage(4, argument_.get(i));
     }
+    if (((bitField0_ & 0x00000008) == 0x00000008)) {
+      output.writeMessage(5, abbreviation_);
+    }
     output.writeRawBytes(unknownFields);
   }
 
@@ -291,6 +329,10 @@ public final class IrSimpleType extends
       size += org.jetbrains.kotlin.protobuf.CodedOutputStream
         .computeMessageSize(4, argument_.get(i));
     }
+    if (((bitField0_ & 0x00000008) == 0x00000008)) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeMessageSize(5, abbreviation_);
+    }
     size += unknownFields.size();
     memoizedSerializedSize = size;
     return size;
@@ -393,6 +435,8 @@ public final class IrSimpleType extends
       bitField0_ = (bitField0_ & ~0x00000004);
       argument_ = java.util.Collections.emptyList();
       bitField0_ = (bitField0_ & ~0x00000008);
+      abbreviation_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.getDefaultInstance();
+      bitField0_ = (bitField0_ & ~0x00000010);
       return this;
     }
 
@@ -433,6 +477,10 @@ public final class IrSimpleType extends
         bitField0_ = (bitField0_ & ~0x00000008);
       }
       result.argument_ = argument_;
+      if (((from_bitField0_ & 0x00000010) == 0x00000010)) {
+        to_bitField0_ |= 0x00000008;
+      }
+      result.abbreviation_ = abbreviation_;
       result.bitField0_ = to_bitField0_;
       return result;
     }
@@ -458,6 +506,9 @@ public final class IrSimpleType extends
         }
         
       }
+      if (other.hasAbbreviation()) {
+        mergeAbbreviation(other.getAbbreviation());
+      }
       setUnknownFields(
           getUnknownFields().concat(other.unknownFields));
       return this;
@@ -490,6 +541,12 @@ public final class IrSimpleType extends
           return false;
         }
       }
+      if (hasAbbreviation()) {
+        if (!getAbbreviation().isInitialized()) {
+          
+          return false;
+        }
+      }
       return true;
     }
 
@@ -789,6 +846,66 @@ public final class IrSimpleType extends
       return this;
     }
 
+    private org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.getDefaultInstance();
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation = 5;</code>
+     */
+    public boolean hasAbbreviation() {
+      return ((bitField0_ & 0x00000010) == 0x00000010);
+    }
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation = 5;</code>
+     */
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation getAbbreviation() {
+      return abbreviation_;
+    }
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation = 5;</code>
+     */
+    public Builder setAbbreviation(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      abbreviation_ = value;
+
+      bitField0_ |= 0x00000010;
+      return this;
+    }
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation = 5;</code>
+     */
+    public Builder setAbbreviation(
+        org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.Builder builderForValue) {
+      abbreviation_ = builderForValue.build();
+
+      bitField0_ |= 0x00000010;
+      return this;
+    }
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation = 5;</code>
+     */
+    public Builder mergeAbbreviation(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation value) {
+      if (((bitField0_ & 0x00000010) == 0x00000010) &&
+          abbreviation_ != org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.getDefaultInstance()) {
+        abbreviation_ =
+          org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.newBuilder(abbreviation_).mergeFrom(value).buildPartial();
+      } else {
+        abbreviation_ = value;
+      }
+
+      bitField0_ |= 0x00000010;
+      return this;
+    }
+    /**
+     * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation = 5;</code>
+     */
+    public Builder clearAbbreviation() {
+      abbreviation_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.getDefaultInstance();
+
+      bitField0_ = (bitField0_ & ~0x00000010);
+      return this;
+    }
+
     // @@protoc_insertion_point(builder_scope:org.jetbrains.kotlin.backend.common.serialization.proto.IrSimpleType)
   }
 
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSimpleTypeOrBuilder.java b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSimpleTypeOrBuilder.java
index 65160f9e760..ebc2137eb45 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSimpleTypeOrBuilder.java
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSimpleTypeOrBuilder.java
@@ -47,4 +47,13 @@ public interface IrSimpleTypeOrBuilder extends
    * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
    */
   int getArgumentCount();
+
+  /**
+   * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation = 5;</code>
+   */
+  boolean hasAbbreviation();
+  /**
+   * <code>optional .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation abbreviation = 5;</code>
+   */
+  org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation getAbbreviation();
 }
\ No newline at end of file
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSymbolKind.java b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSymbolKind.java
index 16045d34dd6..78b81e2c2bc 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSymbolKind.java
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrSymbolKind.java
@@ -72,6 +72,10 @@ public enum IrSymbolKind
    * <code>LOCAL_DELEGATED_PROPERTY_SYMBOL = 14;</code>
    */
   LOCAL_DELEGATED_PROPERTY_SYMBOL(13, 14),
+  /**
+   * <code>TYPEALIAS_SYMBOL = 15;</code>
+   */
+  TYPEALIAS_SYMBOL(14, 15),
   ;
 
   /**
@@ -138,6 +142,10 @@ public enum IrSymbolKind
    * <code>LOCAL_DELEGATED_PROPERTY_SYMBOL = 14;</code>
    */
   public static final int LOCAL_DELEGATED_PROPERTY_SYMBOL_VALUE = 14;
+  /**
+   * <code>TYPEALIAS_SYMBOL = 15;</code>
+   */
+  public static final int TYPEALIAS_SYMBOL_VALUE = 15;
 
 
   public final int getNumber() { return value; }
@@ -158,6 +166,7 @@ public enum IrSymbolKind
       case 12: return RECEIVER_PARAMETER_SYMBOL;
       case 13: return PROPERTY_SYMBOL;
       case 14: return LOCAL_DELEGATED_PROPERTY_SYMBOL;
+      case 15: return TYPEALIAS_SYMBOL;
       default: return null;
     }
   }
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAbbreviation.java b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAbbreviation.java
new file mode 100644
index 00000000000..bb1117cba7c
--- /dev/null
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAbbreviation.java
@@ -0,0 +1,801 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: compiler/ir/serialization.common/src/KotlinIr.proto
+
+package org.jetbrains.kotlin.backend.common.serialization.proto;
+
+/**
+ * Protobuf type {@code org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation}
+ */
+public final class IrTypeAbbreviation extends
+    org.jetbrains.kotlin.protobuf.GeneratedMessageLite implements
+    // @@protoc_insertion_point(message_implements:org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation)
+    IrTypeAbbreviationOrBuilder {
+  // Use IrTypeAbbreviation.newBuilder() to construct.
+  private IrTypeAbbreviation(org.jetbrains.kotlin.protobuf.GeneratedMessageLite.Builder builder) {
+    super(builder);
+    this.unknownFields = builder.getUnknownFields();
+  }
+  private IrTypeAbbreviation(boolean noInit) { this.unknownFields = org.jetbrains.kotlin.protobuf.ByteString.EMPTY;}
+
+  private static final IrTypeAbbreviation defaultInstance;
+  public static IrTypeAbbreviation getDefaultInstance() {
+    return defaultInstance;
+  }
+
+  public IrTypeAbbreviation getDefaultInstanceForType() {
+    return defaultInstance;
+  }
+
+  private final org.jetbrains.kotlin.protobuf.ByteString unknownFields;
+  private IrTypeAbbreviation(
+      org.jetbrains.kotlin.protobuf.CodedInputStream input,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+    initFields();
+    int mutable_bitField0_ = 0;
+    org.jetbrains.kotlin.protobuf.ByteString.Output unknownFieldsOutput =
+        org.jetbrains.kotlin.protobuf.ByteString.newOutput();
+    org.jetbrains.kotlin.protobuf.CodedOutputStream unknownFieldsCodedOutput =
+        org.jetbrains.kotlin.protobuf.CodedOutputStream.newInstance(
+            unknownFieldsOutput);
+    try {
+      boolean done = false;
+      while (!done) {
+        int tag = input.readTag();
+        switch (tag) {
+          case 0:
+            done = true;
+            break;
+          default: {
+            if (!parseUnknownField(input, unknownFieldsCodedOutput,
+                                   extensionRegistry, tag)) {
+              done = true;
+            }
+            break;
+          }
+          case 10: {
+            org.jetbrains.kotlin.backend.common.serialization.proto.Annotations.Builder subBuilder = null;
+            if (((bitField0_ & 0x00000001) == 0x00000001)) {
+              subBuilder = annotations_.toBuilder();
+            }
+            annotations_ = input.readMessage(org.jetbrains.kotlin.backend.common.serialization.proto.Annotations.PARSER, extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom(annotations_);
+              annotations_ = subBuilder.buildPartial();
+            }
+            bitField0_ |= 0x00000001;
+            break;
+          }
+          case 18: {
+            org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol.Builder subBuilder = null;
+            if (((bitField0_ & 0x00000002) == 0x00000002)) {
+              subBuilder = typeAlias_.toBuilder();
+            }
+            typeAlias_ = input.readMessage(org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol.PARSER, extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom(typeAlias_);
+              typeAlias_ = subBuilder.buildPartial();
+            }
+            bitField0_ |= 0x00000002;
+            break;
+          }
+          case 24: {
+            bitField0_ |= 0x00000004;
+            hasQuestionMark_ = input.readBool();
+            break;
+          }
+          case 34: {
+            if (!((mutable_bitField0_ & 0x00000008) == 0x00000008)) {
+              argument_ = new java.util.ArrayList<org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument>();
+              mutable_bitField0_ |= 0x00000008;
+            }
+            argument_.add(input.readMessage(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument.PARSER, extensionRegistry));
+            break;
+          }
+        }
+      }
+    } catch (org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException e) {
+      throw e.setUnfinishedMessage(this);
+    } catch (java.io.IOException e) {
+      throw new org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException(
+          e.getMessage()).setUnfinishedMessage(this);
+    } finally {
+      if (((mutable_bitField0_ & 0x00000008) == 0x00000008)) {
+        argument_ = java.util.Collections.unmodifiableList(argument_);
+      }
+      try {
+        unknownFieldsCodedOutput.flush();
+      } catch (java.io.IOException e) {
+      // Should not happen
+      } finally {
+        unknownFields = unknownFieldsOutput.toByteString();
+      }
+      makeExtensionsImmutable();
+    }
+  }
+  public static org.jetbrains.kotlin.protobuf.Parser<IrTypeAbbreviation> PARSER =
+      new org.jetbrains.kotlin.protobuf.AbstractParser<IrTypeAbbreviation>() {
+    public IrTypeAbbreviation parsePartialFrom(
+        org.jetbrains.kotlin.protobuf.CodedInputStream input,
+        org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+      return new IrTypeAbbreviation(input, extensionRegistry);
+    }
+  };
+
+  @java.lang.Override
+  public org.jetbrains.kotlin.protobuf.Parser<IrTypeAbbreviation> getParserForType() {
+    return PARSER;
+  }
+
+  private int bitField0_;
+  public static final int ANNOTATIONS_FIELD_NUMBER = 1;
+  private org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations_;
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations = 1;</code>
+   */
+  public boolean hasAnnotations() {
+    return ((bitField0_ & 0x00000001) == 0x00000001);
+  }
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations = 1;</code>
+   */
+  public org.jetbrains.kotlin.backend.common.serialization.proto.Annotations getAnnotations() {
+    return annotations_;
+  }
+
+  public static final int TYPE_ALIAS_FIELD_NUMBER = 2;
+  private org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol typeAlias_;
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol type_alias = 2;</code>
+   */
+  public boolean hasTypeAlias() {
+    return ((bitField0_ & 0x00000002) == 0x00000002);
+  }
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol type_alias = 2;</code>
+   */
+  public org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol getTypeAlias() {
+    return typeAlias_;
+  }
+
+  public static final int HAS_QUESTION_MARK_FIELD_NUMBER = 3;
+  private boolean hasQuestionMark_;
+  /**
+   * <code>required bool has_question_mark = 3;</code>
+   */
+  public boolean hasHasQuestionMark() {
+    return ((bitField0_ & 0x00000004) == 0x00000004);
+  }
+  /**
+   * <code>required bool has_question_mark = 3;</code>
+   */
+  public boolean getHasQuestionMark() {
+    return hasQuestionMark_;
+  }
+
+  public static final int ARGUMENT_FIELD_NUMBER = 4;
+  private java.util.List<org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument> argument_;
+  /**
+   * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+   */
+  public java.util.List<org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument> getArgumentList() {
+    return argument_;
+  }
+  /**
+   * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+   */
+  public java.util.List<? extends org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgumentOrBuilder> 
+      getArgumentOrBuilderList() {
+    return argument_;
+  }
+  /**
+   * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+   */
+  public int getArgumentCount() {
+    return argument_.size();
+  }
+  /**
+   * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+   */
+  public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument getArgument(int index) {
+    return argument_.get(index);
+  }
+  /**
+   * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+   */
+  public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgumentOrBuilder getArgumentOrBuilder(
+      int index) {
+    return argument_.get(index);
+  }
+
+  private void initFields() {
+    annotations_ = org.jetbrains.kotlin.backend.common.serialization.proto.Annotations.getDefaultInstance();
+    typeAlias_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol.getDefaultInstance();
+    hasQuestionMark_ = false;
+    argument_ = java.util.Collections.emptyList();
+  }
+  private byte memoizedIsInitialized = -1;
+  public final boolean isInitialized() {
+    byte isInitialized = memoizedIsInitialized;
+    if (isInitialized == 1) return true;
+    if (isInitialized == 0) return false;
+
+    if (!hasAnnotations()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!hasTypeAlias()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!hasHasQuestionMark()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!getAnnotations().isInitialized()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!getTypeAlias().isInitialized()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    for (int i = 0; i < getArgumentCount(); i++) {
+      if (!getArgument(i).isInitialized()) {
+        memoizedIsInitialized = 0;
+        return false;
+      }
+    }
+    memoizedIsInitialized = 1;
+    return true;
+  }
+
+  public void writeTo(org.jetbrains.kotlin.protobuf.CodedOutputStream output)
+                      throws java.io.IOException {
+    getSerializedSize();
+    if (((bitField0_ & 0x00000001) == 0x00000001)) {
+      output.writeMessage(1, annotations_);
+    }
+    if (((bitField0_ & 0x00000002) == 0x00000002)) {
+      output.writeMessage(2, typeAlias_);
+    }
+    if (((bitField0_ & 0x00000004) == 0x00000004)) {
+      output.writeBool(3, hasQuestionMark_);
+    }
+    for (int i = 0; i < argument_.size(); i++) {
+      output.writeMessage(4, argument_.get(i));
+    }
+    output.writeRawBytes(unknownFields);
+  }
+
+  private int memoizedSerializedSize = -1;
+  public int getSerializedSize() {
+    int size = memoizedSerializedSize;
+    if (size != -1) return size;
+
+    size = 0;
+    if (((bitField0_ & 0x00000001) == 0x00000001)) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeMessageSize(1, annotations_);
+    }
+    if (((bitField0_ & 0x00000002) == 0x00000002)) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeMessageSize(2, typeAlias_);
+    }
+    if (((bitField0_ & 0x00000004) == 0x00000004)) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeBoolSize(3, hasQuestionMark_);
+    }
+    for (int i = 0; i < argument_.size(); i++) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeMessageSize(4, argument_.get(i));
+    }
+    size += unknownFields.size();
+    memoizedSerializedSize = size;
+    return size;
+  }
+
+  private static final long serialVersionUID = 0L;
+  @java.lang.Override
+  protected java.lang.Object writeReplace()
+      throws java.io.ObjectStreamException {
+    return super.writeReplace();
+  }
+
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation parseFrom(
+      org.jetbrains.kotlin.protobuf.ByteString data)
+      throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation parseFrom(
+      org.jetbrains.kotlin.protobuf.ByteString data,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation parseFrom(byte[] data)
+      throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation parseFrom(
+      byte[] data,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation parseFrom(java.io.InputStream input)
+      throws java.io.IOException {
+    return PARSER.parseFrom(input);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation parseFrom(
+      java.io.InputStream input,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return PARSER.parseFrom(input, extensionRegistry);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation parseDelimitedFrom(java.io.InputStream input)
+      throws java.io.IOException {
+    return PARSER.parseDelimitedFrom(input);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation parseDelimitedFrom(
+      java.io.InputStream input,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return PARSER.parseDelimitedFrom(input, extensionRegistry);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation parseFrom(
+      org.jetbrains.kotlin.protobuf.CodedInputStream input)
+      throws java.io.IOException {
+    return PARSER.parseFrom(input);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation parseFrom(
+      org.jetbrains.kotlin.protobuf.CodedInputStream input,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return PARSER.parseFrom(input, extensionRegistry);
+  }
+
+  public static Builder newBuilder() { return Builder.create(); }
+  public Builder newBuilderForType() { return newBuilder(); }
+  public static Builder newBuilder(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation prototype) {
+    return newBuilder().mergeFrom(prototype);
+  }
+  public Builder toBuilder() { return newBuilder(this); }
+
+  /**
+   * Protobuf type {@code org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation}
+   */
+  public static final class Builder extends
+      org.jetbrains.kotlin.protobuf.GeneratedMessageLite.Builder<
+        org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation, Builder>
+      implements
+      // @@protoc_insertion_point(builder_implements:org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation)
+      org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviationOrBuilder {
+    // Construct using org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.newBuilder()
+    private Builder() {
+      maybeForceBuilderInitialization();
+    }
+
+    private void maybeForceBuilderInitialization() {
+    }
+    private static Builder create() {
+      return new Builder();
+    }
+
+    public Builder clear() {
+      super.clear();
+      annotations_ = org.jetbrains.kotlin.backend.common.serialization.proto.Annotations.getDefaultInstance();
+      bitField0_ = (bitField0_ & ~0x00000001);
+      typeAlias_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol.getDefaultInstance();
+      bitField0_ = (bitField0_ & ~0x00000002);
+      hasQuestionMark_ = false;
+      bitField0_ = (bitField0_ & ~0x00000004);
+      argument_ = java.util.Collections.emptyList();
+      bitField0_ = (bitField0_ & ~0x00000008);
+      return this;
+    }
+
+    public Builder clone() {
+      return create().mergeFrom(buildPartial());
+    }
+
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation getDefaultInstanceForType() {
+      return org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.getDefaultInstance();
+    }
+
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation build() {
+      org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation result = buildPartial();
+      if (!result.isInitialized()) {
+        throw newUninitializedMessageException(result);
+      }
+      return result;
+    }
+
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation buildPartial() {
+      org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation result = new org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation(this);
+      int from_bitField0_ = bitField0_;
+      int to_bitField0_ = 0;
+      if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+        to_bitField0_ |= 0x00000001;
+      }
+      result.annotations_ = annotations_;
+      if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+        to_bitField0_ |= 0x00000002;
+      }
+      result.typeAlias_ = typeAlias_;
+      if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+        to_bitField0_ |= 0x00000004;
+      }
+      result.hasQuestionMark_ = hasQuestionMark_;
+      if (((bitField0_ & 0x00000008) == 0x00000008)) {
+        argument_ = java.util.Collections.unmodifiableList(argument_);
+        bitField0_ = (bitField0_ & ~0x00000008);
+      }
+      result.argument_ = argument_;
+      result.bitField0_ = to_bitField0_;
+      return result;
+    }
+
+    public Builder mergeFrom(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation other) {
+      if (other == org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation.getDefaultInstance()) return this;
+      if (other.hasAnnotations()) {
+        mergeAnnotations(other.getAnnotations());
+      }
+      if (other.hasTypeAlias()) {
+        mergeTypeAlias(other.getTypeAlias());
+      }
+      if (other.hasHasQuestionMark()) {
+        setHasQuestionMark(other.getHasQuestionMark());
+      }
+      if (!other.argument_.isEmpty()) {
+        if (argument_.isEmpty()) {
+          argument_ = other.argument_;
+          bitField0_ = (bitField0_ & ~0x00000008);
+        } else {
+          ensureArgumentIsMutable();
+          argument_.addAll(other.argument_);
+        }
+        
+      }
+      setUnknownFields(
+          getUnknownFields().concat(other.unknownFields));
+      return this;
+    }
+
+    public final boolean isInitialized() {
+      if (!hasAnnotations()) {
+        
+        return false;
+      }
+      if (!hasTypeAlias()) {
+        
+        return false;
+      }
+      if (!hasHasQuestionMark()) {
+        
+        return false;
+      }
+      if (!getAnnotations().isInitialized()) {
+        
+        return false;
+      }
+      if (!getTypeAlias().isInitialized()) {
+        
+        return false;
+      }
+      for (int i = 0; i < getArgumentCount(); i++) {
+        if (!getArgument(i).isInitialized()) {
+          
+          return false;
+        }
+      }
+      return true;
+    }
+
+    public Builder mergeFrom(
+        org.jetbrains.kotlin.protobuf.CodedInputStream input,
+        org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation parsedMessage = null;
+      try {
+        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+      } catch (org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException e) {
+        parsedMessage = (org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation) e.getUnfinishedMessage();
+        throw e;
+      } finally {
+        if (parsedMessage != null) {
+          mergeFrom(parsedMessage);
+        }
+      }
+      return this;
+    }
+    private int bitField0_;
+
+    private org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations_ = org.jetbrains.kotlin.backend.common.serialization.proto.Annotations.getDefaultInstance();
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations = 1;</code>
+     */
+    public boolean hasAnnotations() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations = 1;</code>
+     */
+    public org.jetbrains.kotlin.backend.common.serialization.proto.Annotations getAnnotations() {
+      return annotations_;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations = 1;</code>
+     */
+    public Builder setAnnotations(org.jetbrains.kotlin.backend.common.serialization.proto.Annotations value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      annotations_ = value;
+
+      bitField0_ |= 0x00000001;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations = 1;</code>
+     */
+    public Builder setAnnotations(
+        org.jetbrains.kotlin.backend.common.serialization.proto.Annotations.Builder builderForValue) {
+      annotations_ = builderForValue.build();
+
+      bitField0_ |= 0x00000001;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations = 1;</code>
+     */
+    public Builder mergeAnnotations(org.jetbrains.kotlin.backend.common.serialization.proto.Annotations value) {
+      if (((bitField0_ & 0x00000001) == 0x00000001) &&
+          annotations_ != org.jetbrains.kotlin.backend.common.serialization.proto.Annotations.getDefaultInstance()) {
+        annotations_ =
+          org.jetbrains.kotlin.backend.common.serialization.proto.Annotations.newBuilder(annotations_).mergeFrom(value).buildPartial();
+      } else {
+        annotations_ = value;
+      }
+
+      bitField0_ |= 0x00000001;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations = 1;</code>
+     */
+    public Builder clearAnnotations() {
+      annotations_ = org.jetbrains.kotlin.backend.common.serialization.proto.Annotations.getDefaultInstance();
+
+      bitField0_ = (bitField0_ & ~0x00000001);
+      return this;
+    }
+
+    private org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol typeAlias_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol.getDefaultInstance();
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol type_alias = 2;</code>
+     */
+    public boolean hasTypeAlias() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol type_alias = 2;</code>
+     */
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol getTypeAlias() {
+      return typeAlias_;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol type_alias = 2;</code>
+     */
+    public Builder setTypeAlias(org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      typeAlias_ = value;
+
+      bitField0_ |= 0x00000002;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol type_alias = 2;</code>
+     */
+    public Builder setTypeAlias(
+        org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol.Builder builderForValue) {
+      typeAlias_ = builderForValue.build();
+
+      bitField0_ |= 0x00000002;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol type_alias = 2;</code>
+     */
+    public Builder mergeTypeAlias(org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol value) {
+      if (((bitField0_ & 0x00000002) == 0x00000002) &&
+          typeAlias_ != org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol.getDefaultInstance()) {
+        typeAlias_ =
+          org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol.newBuilder(typeAlias_).mergeFrom(value).buildPartial();
+      } else {
+        typeAlias_ = value;
+      }
+
+      bitField0_ |= 0x00000002;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol type_alias = 2;</code>
+     */
+    public Builder clearTypeAlias() {
+      typeAlias_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol.getDefaultInstance();
+
+      bitField0_ = (bitField0_ & ~0x00000002);
+      return this;
+    }
+
+    private boolean hasQuestionMark_ ;
+    /**
+     * <code>required bool has_question_mark = 3;</code>
+     */
+    public boolean hasHasQuestionMark() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>required bool has_question_mark = 3;</code>
+     */
+    public boolean getHasQuestionMark() {
+      return hasQuestionMark_;
+    }
+    /**
+     * <code>required bool has_question_mark = 3;</code>
+     */
+    public Builder setHasQuestionMark(boolean value) {
+      bitField0_ |= 0x00000004;
+      hasQuestionMark_ = value;
+      
+      return this;
+    }
+    /**
+     * <code>required bool has_question_mark = 3;</code>
+     */
+    public Builder clearHasQuestionMark() {
+      bitField0_ = (bitField0_ & ~0x00000004);
+      hasQuestionMark_ = false;
+      
+      return this;
+    }
+
+    private java.util.List<org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument> argument_ =
+      java.util.Collections.emptyList();
+    private void ensureArgumentIsMutable() {
+      if (!((bitField0_ & 0x00000008) == 0x00000008)) {
+        argument_ = new java.util.ArrayList<org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument>(argument_);
+        bitField0_ |= 0x00000008;
+       }
+    }
+
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public java.util.List<org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument> getArgumentList() {
+      return java.util.Collections.unmodifiableList(argument_);
+    }
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public int getArgumentCount() {
+      return argument_.size();
+    }
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument getArgument(int index) {
+      return argument_.get(index);
+    }
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public Builder setArgument(
+        int index, org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      ensureArgumentIsMutable();
+      argument_.set(index, value);
+
+      return this;
+    }
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public Builder setArgument(
+        int index, org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument.Builder builderForValue) {
+      ensureArgumentIsMutable();
+      argument_.set(index, builderForValue.build());
+
+      return this;
+    }
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public Builder addArgument(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      ensureArgumentIsMutable();
+      argument_.add(value);
+
+      return this;
+    }
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public Builder addArgument(
+        int index, org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      ensureArgumentIsMutable();
+      argument_.add(index, value);
+
+      return this;
+    }
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public Builder addArgument(
+        org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument.Builder builderForValue) {
+      ensureArgumentIsMutable();
+      argument_.add(builderForValue.build());
+
+      return this;
+    }
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public Builder addArgument(
+        int index, org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument.Builder builderForValue) {
+      ensureArgumentIsMutable();
+      argument_.add(index, builderForValue.build());
+
+      return this;
+    }
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public Builder addAllArgument(
+        java.lang.Iterable<? extends org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument> values) {
+      ensureArgumentIsMutable();
+      org.jetbrains.kotlin.protobuf.AbstractMessageLite.Builder.addAll(
+          values, argument_);
+
+      return this;
+    }
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public Builder clearArgument() {
+      argument_ = java.util.Collections.emptyList();
+      bitField0_ = (bitField0_ & ~0x00000008);
+
+      return this;
+    }
+    /**
+     * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+     */
+    public Builder removeArgument(int index) {
+      ensureArgumentIsMutable();
+      argument_.remove(index);
+
+      return this;
+    }
+
+    // @@protoc_insertion_point(builder_scope:org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation)
+  }
+
+  static {
+    defaultInstance = new IrTypeAbbreviation(true);
+    defaultInstance.initFields();
+  }
+
+  // @@protoc_insertion_point(class_scope:org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation)
+}
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAbbreviationOrBuilder.java b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAbbreviationOrBuilder.java
new file mode 100644
index 00000000000..01b964f1bd4
--- /dev/null
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAbbreviationOrBuilder.java
@@ -0,0 +1,50 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: compiler/ir/serialization.common/src/KotlinIr.proto
+
+package org.jetbrains.kotlin.backend.common.serialization.proto;
+
+public interface IrTypeAbbreviationOrBuilder extends
+    // @@protoc_insertion_point(interface_extends:org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAbbreviation)
+    org.jetbrains.kotlin.protobuf.MessageLiteOrBuilder {
+
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations = 1;</code>
+   */
+  boolean hasAnnotations();
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Annotations annotations = 1;</code>
+   */
+  org.jetbrains.kotlin.backend.common.serialization.proto.Annotations getAnnotations();
+
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol type_alias = 2;</code>
+   */
+  boolean hasTypeAlias();
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol type_alias = 2;</code>
+   */
+  org.jetbrains.kotlin.backend.common.serialization.proto.IrSymbol getTypeAlias();
+
+  /**
+   * <code>required bool has_question_mark = 3;</code>
+   */
+  boolean hasHasQuestionMark();
+  /**
+   * <code>required bool has_question_mark = 3;</code>
+   */
+  boolean getHasQuestionMark();
+
+  /**
+   * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+   */
+  java.util.List<org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument> 
+      getArgumentList();
+  /**
+   * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+   */
+  org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument getArgument(int index);
+  /**
+   * <code>repeated .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeArgument argument = 4;</code>
+   */
+  int getArgumentCount();
+}
\ No newline at end of file
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAlias.java b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAlias.java
new file mode 100644
index 00000000000..23b8f4fffaf
--- /dev/null
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAlias.java
@@ -0,0 +1,956 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: compiler/ir/serialization.common/src/KotlinIr.proto
+
+package org.jetbrains.kotlin.backend.common.serialization.proto;
+
+/**
+ * Protobuf type {@code org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias}
+ */
+public final class IrTypeAlias extends
+    org.jetbrains.kotlin.protobuf.GeneratedMessageLite implements
+    // @@protoc_insertion_point(message_implements:org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias)
+    IrTypeAliasOrBuilder {
+  // Use IrTypeAlias.newBuilder() to construct.
+  private IrTypeAlias(org.jetbrains.kotlin.protobuf.GeneratedMessageLite.Builder builder) {
+    super(builder);
+    this.unknownFields = builder.getUnknownFields();
+  }
+  private IrTypeAlias(boolean noInit) { this.unknownFields = org.jetbrains.kotlin.protobuf.ByteString.EMPTY;}
+
+  private static final IrTypeAlias defaultInstance;
+  public static IrTypeAlias getDefaultInstance() {
+    return defaultInstance;
+  }
+
+  public IrTypeAlias getDefaultInstanceForType() {
+    return defaultInstance;
+  }
+
+  private final org.jetbrains.kotlin.protobuf.ByteString unknownFields;
+  private IrTypeAlias(
+      org.jetbrains.kotlin.protobuf.CodedInputStream input,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+    initFields();
+    int mutable_bitField0_ = 0;
+    org.jetbrains.kotlin.protobuf.ByteString.Output unknownFieldsOutput =
+        org.jetbrains.kotlin.protobuf.ByteString.newOutput();
+    org.jetbrains.kotlin.protobuf.CodedOutputStream unknownFieldsCodedOutput =
+        org.jetbrains.kotlin.protobuf.CodedOutputStream.newInstance(
+            unknownFieldsOutput);
+    try {
+      boolean done = false;
+      while (!done) {
+        int tag = input.readTag();
+        switch (tag) {
+          case 0:
+            done = true;
+            break;
+          default: {
+            if (!parseUnknownField(input, unknownFieldsCodedOutput,
+                                   extensionRegistry, tag)) {
+              done = true;
+            }
+            break;
+          }
+          case 10: {
+            org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase.Builder subBuilder = null;
+            if (((bitField0_ & 0x00000001) == 0x00000001)) {
+              subBuilder = base_.toBuilder();
+            }
+            base_ = input.readMessage(org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase.PARSER, extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom(base_);
+              base_ = subBuilder.buildPartial();
+            }
+            bitField0_ |= 0x00000001;
+            break;
+          }
+          case 18: {
+            org.jetbrains.kotlin.backend.common.serialization.proto.String.Builder subBuilder = null;
+            if (((bitField0_ & 0x00000002) == 0x00000002)) {
+              subBuilder = name_.toBuilder();
+            }
+            name_ = input.readMessage(org.jetbrains.kotlin.backend.common.serialization.proto.String.PARSER, extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom(name_);
+              name_ = subBuilder.buildPartial();
+            }
+            bitField0_ |= 0x00000002;
+            break;
+          }
+          case 26: {
+            org.jetbrains.kotlin.backend.common.serialization.proto.Visibility.Builder subBuilder = null;
+            if (((bitField0_ & 0x00000004) == 0x00000004)) {
+              subBuilder = visibility_.toBuilder();
+            }
+            visibility_ = input.readMessage(org.jetbrains.kotlin.backend.common.serialization.proto.Visibility.PARSER, extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom(visibility_);
+              visibility_ = subBuilder.buildPartial();
+            }
+            bitField0_ |= 0x00000004;
+            break;
+          }
+          case 34: {
+            org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer.Builder subBuilder = null;
+            if (((bitField0_ & 0x00000008) == 0x00000008)) {
+              subBuilder = typeParameters_.toBuilder();
+            }
+            typeParameters_ = input.readMessage(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer.PARSER, extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom(typeParameters_);
+              typeParameters_ = subBuilder.buildPartial();
+            }
+            bitField0_ |= 0x00000008;
+            break;
+          }
+          case 42: {
+            org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex.Builder subBuilder = null;
+            if (((bitField0_ & 0x00000010) == 0x00000010)) {
+              subBuilder = expandedType_.toBuilder();
+            }
+            expandedType_ = input.readMessage(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex.PARSER, extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom(expandedType_);
+              expandedType_ = subBuilder.buildPartial();
+            }
+            bitField0_ |= 0x00000010;
+            break;
+          }
+          case 48: {
+            bitField0_ |= 0x00000020;
+            isActual_ = input.readBool();
+            break;
+          }
+        }
+      }
+    } catch (org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException e) {
+      throw e.setUnfinishedMessage(this);
+    } catch (java.io.IOException e) {
+      throw new org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException(
+          e.getMessage()).setUnfinishedMessage(this);
+    } finally {
+      try {
+        unknownFieldsCodedOutput.flush();
+      } catch (java.io.IOException e) {
+      // Should not happen
+      } finally {
+        unknownFields = unknownFieldsOutput.toByteString();
+      }
+      makeExtensionsImmutable();
+    }
+  }
+  public static org.jetbrains.kotlin.protobuf.Parser<IrTypeAlias> PARSER =
+      new org.jetbrains.kotlin.protobuf.AbstractParser<IrTypeAlias>() {
+    public IrTypeAlias parsePartialFrom(
+        org.jetbrains.kotlin.protobuf.CodedInputStream input,
+        org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+      return new IrTypeAlias(input, extensionRegistry);
+    }
+  };
+
+  @java.lang.Override
+  public org.jetbrains.kotlin.protobuf.Parser<IrTypeAlias> getParserForType() {
+    return PARSER;
+  }
+
+  private int bitField0_;
+  public static final int BASE_FIELD_NUMBER = 1;
+  private org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base_;
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base = 1;</code>
+   */
+  public boolean hasBase() {
+    return ((bitField0_ & 0x00000001) == 0x00000001);
+  }
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base = 1;</code>
+   */
+  public org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase getBase() {
+    return base_;
+  }
+
+  public static final int NAME_FIELD_NUMBER = 2;
+  private org.jetbrains.kotlin.backend.common.serialization.proto.String name_;
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.String name = 2;</code>
+   */
+  public boolean hasName() {
+    return ((bitField0_ & 0x00000002) == 0x00000002);
+  }
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.String name = 2;</code>
+   */
+  public org.jetbrains.kotlin.backend.common.serialization.proto.String getName() {
+    return name_;
+  }
+
+  public static final int VISIBILITY_FIELD_NUMBER = 3;
+  private org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility_;
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility = 3;</code>
+   */
+  public boolean hasVisibility() {
+    return ((bitField0_ & 0x00000004) == 0x00000004);
+  }
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility = 3;</code>
+   */
+  public org.jetbrains.kotlin.backend.common.serialization.proto.Visibility getVisibility() {
+    return visibility_;
+  }
+
+  public static final int TYPE_PARAMETERS_FIELD_NUMBER = 4;
+  private org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer typeParameters_;
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer type_parameters = 4;</code>
+   */
+  public boolean hasTypeParameters() {
+    return ((bitField0_ & 0x00000008) == 0x00000008);
+  }
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer type_parameters = 4;</code>
+   */
+  public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer getTypeParameters() {
+    return typeParameters_;
+  }
+
+  public static final int EXPANDED_TYPE_FIELD_NUMBER = 5;
+  private org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expandedType_;
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expanded_type = 5;</code>
+   */
+  public boolean hasExpandedType() {
+    return ((bitField0_ & 0x00000010) == 0x00000010);
+  }
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expanded_type = 5;</code>
+   */
+  public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex getExpandedType() {
+    return expandedType_;
+  }
+
+  public static final int IS_ACTUAL_FIELD_NUMBER = 6;
+  private boolean isActual_;
+  /**
+   * <code>required bool is_actual = 6;</code>
+   */
+  public boolean hasIsActual() {
+    return ((bitField0_ & 0x00000020) == 0x00000020);
+  }
+  /**
+   * <code>required bool is_actual = 6;</code>
+   */
+  public boolean getIsActual() {
+    return isActual_;
+  }
+
+  private void initFields() {
+    base_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase.getDefaultInstance();
+    name_ = org.jetbrains.kotlin.backend.common.serialization.proto.String.getDefaultInstance();
+    visibility_ = org.jetbrains.kotlin.backend.common.serialization.proto.Visibility.getDefaultInstance();
+    typeParameters_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer.getDefaultInstance();
+    expandedType_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex.getDefaultInstance();
+    isActual_ = false;
+  }
+  private byte memoizedIsInitialized = -1;
+  public final boolean isInitialized() {
+    byte isInitialized = memoizedIsInitialized;
+    if (isInitialized == 1) return true;
+    if (isInitialized == 0) return false;
+
+    if (!hasBase()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!hasName()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!hasVisibility()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!hasTypeParameters()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!hasExpandedType()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!hasIsActual()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!getBase().isInitialized()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!getName().isInitialized()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!getVisibility().isInitialized()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!getTypeParameters().isInitialized()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    if (!getExpandedType().isInitialized()) {
+      memoizedIsInitialized = 0;
+      return false;
+    }
+    memoizedIsInitialized = 1;
+    return true;
+  }
+
+  public void writeTo(org.jetbrains.kotlin.protobuf.CodedOutputStream output)
+                      throws java.io.IOException {
+    getSerializedSize();
+    if (((bitField0_ & 0x00000001) == 0x00000001)) {
+      output.writeMessage(1, base_);
+    }
+    if (((bitField0_ & 0x00000002) == 0x00000002)) {
+      output.writeMessage(2, name_);
+    }
+    if (((bitField0_ & 0x00000004) == 0x00000004)) {
+      output.writeMessage(3, visibility_);
+    }
+    if (((bitField0_ & 0x00000008) == 0x00000008)) {
+      output.writeMessage(4, typeParameters_);
+    }
+    if (((bitField0_ & 0x00000010) == 0x00000010)) {
+      output.writeMessage(5, expandedType_);
+    }
+    if (((bitField0_ & 0x00000020) == 0x00000020)) {
+      output.writeBool(6, isActual_);
+    }
+    output.writeRawBytes(unknownFields);
+  }
+
+  private int memoizedSerializedSize = -1;
+  public int getSerializedSize() {
+    int size = memoizedSerializedSize;
+    if (size != -1) return size;
+
+    size = 0;
+    if (((bitField0_ & 0x00000001) == 0x00000001)) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeMessageSize(1, base_);
+    }
+    if (((bitField0_ & 0x00000002) == 0x00000002)) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeMessageSize(2, name_);
+    }
+    if (((bitField0_ & 0x00000004) == 0x00000004)) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeMessageSize(3, visibility_);
+    }
+    if (((bitField0_ & 0x00000008) == 0x00000008)) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeMessageSize(4, typeParameters_);
+    }
+    if (((bitField0_ & 0x00000010) == 0x00000010)) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeMessageSize(5, expandedType_);
+    }
+    if (((bitField0_ & 0x00000020) == 0x00000020)) {
+      size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+        .computeBoolSize(6, isActual_);
+    }
+    size += unknownFields.size();
+    memoizedSerializedSize = size;
+    return size;
+  }
+
+  private static final long serialVersionUID = 0L;
+  @java.lang.Override
+  protected java.lang.Object writeReplace()
+      throws java.io.ObjectStreamException {
+    return super.writeReplace();
+  }
+
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias parseFrom(
+      org.jetbrains.kotlin.protobuf.ByteString data)
+      throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias parseFrom(
+      org.jetbrains.kotlin.protobuf.ByteString data,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias parseFrom(byte[] data)
+      throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias parseFrom(
+      byte[] data,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias parseFrom(java.io.InputStream input)
+      throws java.io.IOException {
+    return PARSER.parseFrom(input);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias parseFrom(
+      java.io.InputStream input,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return PARSER.parseFrom(input, extensionRegistry);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias parseDelimitedFrom(java.io.InputStream input)
+      throws java.io.IOException {
+    return PARSER.parseDelimitedFrom(input);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias parseDelimitedFrom(
+      java.io.InputStream input,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return PARSER.parseDelimitedFrom(input, extensionRegistry);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias parseFrom(
+      org.jetbrains.kotlin.protobuf.CodedInputStream input)
+      throws java.io.IOException {
+    return PARSER.parseFrom(input);
+  }
+  public static org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias parseFrom(
+      org.jetbrains.kotlin.protobuf.CodedInputStream input,
+      org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return PARSER.parseFrom(input, extensionRegistry);
+  }
+
+  public static Builder newBuilder() { return Builder.create(); }
+  public Builder newBuilderForType() { return newBuilder(); }
+  public static Builder newBuilder(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias prototype) {
+    return newBuilder().mergeFrom(prototype);
+  }
+  public Builder toBuilder() { return newBuilder(this); }
+
+  /**
+   * Protobuf type {@code org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias}
+   */
+  public static final class Builder extends
+      org.jetbrains.kotlin.protobuf.GeneratedMessageLite.Builder<
+        org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias, Builder>
+      implements
+      // @@protoc_insertion_point(builder_implements:org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias)
+      org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAliasOrBuilder {
+    // Construct using org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias.newBuilder()
+    private Builder() {
+      maybeForceBuilderInitialization();
+    }
+
+    private void maybeForceBuilderInitialization() {
+    }
+    private static Builder create() {
+      return new Builder();
+    }
+
+    public Builder clear() {
+      super.clear();
+      base_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase.getDefaultInstance();
+      bitField0_ = (bitField0_ & ~0x00000001);
+      name_ = org.jetbrains.kotlin.backend.common.serialization.proto.String.getDefaultInstance();
+      bitField0_ = (bitField0_ & ~0x00000002);
+      visibility_ = org.jetbrains.kotlin.backend.common.serialization.proto.Visibility.getDefaultInstance();
+      bitField0_ = (bitField0_ & ~0x00000004);
+      typeParameters_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer.getDefaultInstance();
+      bitField0_ = (bitField0_ & ~0x00000008);
+      expandedType_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex.getDefaultInstance();
+      bitField0_ = (bitField0_ & ~0x00000010);
+      isActual_ = false;
+      bitField0_ = (bitField0_ & ~0x00000020);
+      return this;
+    }
+
+    public Builder clone() {
+      return create().mergeFrom(buildPartial());
+    }
+
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias getDefaultInstanceForType() {
+      return org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias.getDefaultInstance();
+    }
+
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias build() {
+      org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias result = buildPartial();
+      if (!result.isInitialized()) {
+        throw newUninitializedMessageException(result);
+      }
+      return result;
+    }
+
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias buildPartial() {
+      org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias result = new org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias(this);
+      int from_bitField0_ = bitField0_;
+      int to_bitField0_ = 0;
+      if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+        to_bitField0_ |= 0x00000001;
+      }
+      result.base_ = base_;
+      if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+        to_bitField0_ |= 0x00000002;
+      }
+      result.name_ = name_;
+      if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+        to_bitField0_ |= 0x00000004;
+      }
+      result.visibility_ = visibility_;
+      if (((from_bitField0_ & 0x00000008) == 0x00000008)) {
+        to_bitField0_ |= 0x00000008;
+      }
+      result.typeParameters_ = typeParameters_;
+      if (((from_bitField0_ & 0x00000010) == 0x00000010)) {
+        to_bitField0_ |= 0x00000010;
+      }
+      result.expandedType_ = expandedType_;
+      if (((from_bitField0_ & 0x00000020) == 0x00000020)) {
+        to_bitField0_ |= 0x00000020;
+      }
+      result.isActual_ = isActual_;
+      result.bitField0_ = to_bitField0_;
+      return result;
+    }
+
+    public Builder mergeFrom(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias other) {
+      if (other == org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias.getDefaultInstance()) return this;
+      if (other.hasBase()) {
+        mergeBase(other.getBase());
+      }
+      if (other.hasName()) {
+        mergeName(other.getName());
+      }
+      if (other.hasVisibility()) {
+        mergeVisibility(other.getVisibility());
+      }
+      if (other.hasTypeParameters()) {
+        mergeTypeParameters(other.getTypeParameters());
+      }
+      if (other.hasExpandedType()) {
+        mergeExpandedType(other.getExpandedType());
+      }
+      if (other.hasIsActual()) {
+        setIsActual(other.getIsActual());
+      }
+      setUnknownFields(
+          getUnknownFields().concat(other.unknownFields));
+      return this;
+    }
+
+    public final boolean isInitialized() {
+      if (!hasBase()) {
+        
+        return false;
+      }
+      if (!hasName()) {
+        
+        return false;
+      }
+      if (!hasVisibility()) {
+        
+        return false;
+      }
+      if (!hasTypeParameters()) {
+        
+        return false;
+      }
+      if (!hasExpandedType()) {
+        
+        return false;
+      }
+      if (!hasIsActual()) {
+        
+        return false;
+      }
+      if (!getBase().isInitialized()) {
+        
+        return false;
+      }
+      if (!getName().isInitialized()) {
+        
+        return false;
+      }
+      if (!getVisibility().isInitialized()) {
+        
+        return false;
+      }
+      if (!getTypeParameters().isInitialized()) {
+        
+        return false;
+      }
+      if (!getExpandedType().isInitialized()) {
+        
+        return false;
+      }
+      return true;
+    }
+
+    public Builder mergeFrom(
+        org.jetbrains.kotlin.protobuf.CodedInputStream input,
+        org.jetbrains.kotlin.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias parsedMessage = null;
+      try {
+        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+      } catch (org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException e) {
+        parsedMessage = (org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias) e.getUnfinishedMessage();
+        throw e;
+      } finally {
+        if (parsedMessage != null) {
+          mergeFrom(parsedMessage);
+        }
+      }
+      return this;
+    }
+    private int bitField0_;
+
+    private org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase.getDefaultInstance();
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base = 1;</code>
+     */
+    public boolean hasBase() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base = 1;</code>
+     */
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase getBase() {
+      return base_;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base = 1;</code>
+     */
+    public Builder setBase(org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      base_ = value;
+
+      bitField0_ |= 0x00000001;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base = 1;</code>
+     */
+    public Builder setBase(
+        org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase.Builder builderForValue) {
+      base_ = builderForValue.build();
+
+      bitField0_ |= 0x00000001;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base = 1;</code>
+     */
+    public Builder mergeBase(org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase value) {
+      if (((bitField0_ & 0x00000001) == 0x00000001) &&
+          base_ != org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase.getDefaultInstance()) {
+        base_ =
+          org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase.newBuilder(base_).mergeFrom(value).buildPartial();
+      } else {
+        base_ = value;
+      }
+
+      bitField0_ |= 0x00000001;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base = 1;</code>
+     */
+    public Builder clearBase() {
+      base_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase.getDefaultInstance();
+
+      bitField0_ = (bitField0_ & ~0x00000001);
+      return this;
+    }
+
+    private org.jetbrains.kotlin.backend.common.serialization.proto.String name_ = org.jetbrains.kotlin.backend.common.serialization.proto.String.getDefaultInstance();
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.String name = 2;</code>
+     */
+    public boolean hasName() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.String name = 2;</code>
+     */
+    public org.jetbrains.kotlin.backend.common.serialization.proto.String getName() {
+      return name_;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.String name = 2;</code>
+     */
+    public Builder setName(org.jetbrains.kotlin.backend.common.serialization.proto.String value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      name_ = value;
+
+      bitField0_ |= 0x00000002;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.String name = 2;</code>
+     */
+    public Builder setName(
+        org.jetbrains.kotlin.backend.common.serialization.proto.String.Builder builderForValue) {
+      name_ = builderForValue.build();
+
+      bitField0_ |= 0x00000002;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.String name = 2;</code>
+     */
+    public Builder mergeName(org.jetbrains.kotlin.backend.common.serialization.proto.String value) {
+      if (((bitField0_ & 0x00000002) == 0x00000002) &&
+          name_ != org.jetbrains.kotlin.backend.common.serialization.proto.String.getDefaultInstance()) {
+        name_ =
+          org.jetbrains.kotlin.backend.common.serialization.proto.String.newBuilder(name_).mergeFrom(value).buildPartial();
+      } else {
+        name_ = value;
+      }
+
+      bitField0_ |= 0x00000002;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.String name = 2;</code>
+     */
+    public Builder clearName() {
+      name_ = org.jetbrains.kotlin.backend.common.serialization.proto.String.getDefaultInstance();
+
+      bitField0_ = (bitField0_ & ~0x00000002);
+      return this;
+    }
+
+    private org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility_ = org.jetbrains.kotlin.backend.common.serialization.proto.Visibility.getDefaultInstance();
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility = 3;</code>
+     */
+    public boolean hasVisibility() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility = 3;</code>
+     */
+    public org.jetbrains.kotlin.backend.common.serialization.proto.Visibility getVisibility() {
+      return visibility_;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility = 3;</code>
+     */
+    public Builder setVisibility(org.jetbrains.kotlin.backend.common.serialization.proto.Visibility value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      visibility_ = value;
+
+      bitField0_ |= 0x00000004;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility = 3;</code>
+     */
+    public Builder setVisibility(
+        org.jetbrains.kotlin.backend.common.serialization.proto.Visibility.Builder builderForValue) {
+      visibility_ = builderForValue.build();
+
+      bitField0_ |= 0x00000004;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility = 3;</code>
+     */
+    public Builder mergeVisibility(org.jetbrains.kotlin.backend.common.serialization.proto.Visibility value) {
+      if (((bitField0_ & 0x00000004) == 0x00000004) &&
+          visibility_ != org.jetbrains.kotlin.backend.common.serialization.proto.Visibility.getDefaultInstance()) {
+        visibility_ =
+          org.jetbrains.kotlin.backend.common.serialization.proto.Visibility.newBuilder(visibility_).mergeFrom(value).buildPartial();
+      } else {
+        visibility_ = value;
+      }
+
+      bitField0_ |= 0x00000004;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility = 3;</code>
+     */
+    public Builder clearVisibility() {
+      visibility_ = org.jetbrains.kotlin.backend.common.serialization.proto.Visibility.getDefaultInstance();
+
+      bitField0_ = (bitField0_ & ~0x00000004);
+      return this;
+    }
+
+    private org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer typeParameters_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer.getDefaultInstance();
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer type_parameters = 4;</code>
+     */
+    public boolean hasTypeParameters() {
+      return ((bitField0_ & 0x00000008) == 0x00000008);
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer type_parameters = 4;</code>
+     */
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer getTypeParameters() {
+      return typeParameters_;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer type_parameters = 4;</code>
+     */
+    public Builder setTypeParameters(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      typeParameters_ = value;
+
+      bitField0_ |= 0x00000008;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer type_parameters = 4;</code>
+     */
+    public Builder setTypeParameters(
+        org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer.Builder builderForValue) {
+      typeParameters_ = builderForValue.build();
+
+      bitField0_ |= 0x00000008;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer type_parameters = 4;</code>
+     */
+    public Builder mergeTypeParameters(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer value) {
+      if (((bitField0_ & 0x00000008) == 0x00000008) &&
+          typeParameters_ != org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer.getDefaultInstance()) {
+        typeParameters_ =
+          org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer.newBuilder(typeParameters_).mergeFrom(value).buildPartial();
+      } else {
+        typeParameters_ = value;
+      }
+
+      bitField0_ |= 0x00000008;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer type_parameters = 4;</code>
+     */
+    public Builder clearTypeParameters() {
+      typeParameters_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer.getDefaultInstance();
+
+      bitField0_ = (bitField0_ & ~0x00000008);
+      return this;
+    }
+
+    private org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expandedType_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex.getDefaultInstance();
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expanded_type = 5;</code>
+     */
+    public boolean hasExpandedType() {
+      return ((bitField0_ & 0x00000010) == 0x00000010);
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expanded_type = 5;</code>
+     */
+    public org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex getExpandedType() {
+      return expandedType_;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expanded_type = 5;</code>
+     */
+    public Builder setExpandedType(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex value) {
+      if (value == null) {
+        throw new NullPointerException();
+      }
+      expandedType_ = value;
+
+      bitField0_ |= 0x00000010;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expanded_type = 5;</code>
+     */
+    public Builder setExpandedType(
+        org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex.Builder builderForValue) {
+      expandedType_ = builderForValue.build();
+
+      bitField0_ |= 0x00000010;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expanded_type = 5;</code>
+     */
+    public Builder mergeExpandedType(org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex value) {
+      if (((bitField0_ & 0x00000010) == 0x00000010) &&
+          expandedType_ != org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex.getDefaultInstance()) {
+        expandedType_ =
+          org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex.newBuilder(expandedType_).mergeFrom(value).buildPartial();
+      } else {
+        expandedType_ = value;
+      }
+
+      bitField0_ |= 0x00000010;
+      return this;
+    }
+    /**
+     * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expanded_type = 5;</code>
+     */
+    public Builder clearExpandedType() {
+      expandedType_ = org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex.getDefaultInstance();
+
+      bitField0_ = (bitField0_ & ~0x00000010);
+      return this;
+    }
+
+    private boolean isActual_ ;
+    /**
+     * <code>required bool is_actual = 6;</code>
+     */
+    public boolean hasIsActual() {
+      return ((bitField0_ & 0x00000020) == 0x00000020);
+    }
+    /**
+     * <code>required bool is_actual = 6;</code>
+     */
+    public boolean getIsActual() {
+      return isActual_;
+    }
+    /**
+     * <code>required bool is_actual = 6;</code>
+     */
+    public Builder setIsActual(boolean value) {
+      bitField0_ |= 0x00000020;
+      isActual_ = value;
+      
+      return this;
+    }
+    /**
+     * <code>required bool is_actual = 6;</code>
+     */
+    public Builder clearIsActual() {
+      bitField0_ = (bitField0_ & ~0x00000020);
+      isActual_ = false;
+      
+      return this;
+    }
+
+    // @@protoc_insertion_point(builder_scope:org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias)
+  }
+
+  static {
+    defaultInstance = new IrTypeAlias(true);
+    defaultInstance.initFields();
+  }
+
+  // @@protoc_insertion_point(class_scope:org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias)
+}
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAliasOrBuilder.java b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAliasOrBuilder.java
new file mode 100644
index 00000000000..e5e811312dd
--- /dev/null
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/proto/IrTypeAliasOrBuilder.java
@@ -0,0 +1,63 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: compiler/ir/serialization.common/src/KotlinIr.proto
+
+package org.jetbrains.kotlin.backend.common.serialization.proto;
+
+public interface IrTypeAliasOrBuilder extends
+    // @@protoc_insertion_point(interface_extends:org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeAlias)
+    org.jetbrains.kotlin.protobuf.MessageLiteOrBuilder {
+
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base = 1;</code>
+   */
+  boolean hasBase();
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase base = 1;</code>
+   */
+  org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclarationBase getBase();
+
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.String name = 2;</code>
+   */
+  boolean hasName();
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.String name = 2;</code>
+   */
+  org.jetbrains.kotlin.backend.common.serialization.proto.String getName();
+
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility = 3;</code>
+   */
+  boolean hasVisibility();
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.Visibility visibility = 3;</code>
+   */
+  org.jetbrains.kotlin.backend.common.serialization.proto.Visibility getVisibility();
+
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer type_parameters = 4;</code>
+   */
+  boolean hasTypeParameters();
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer type_parameters = 4;</code>
+   */
+  org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeParameterContainer getTypeParameters();
+
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expanded_type = 5;</code>
+   */
+  boolean hasExpandedType();
+  /**
+   * <code>required .org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex expanded_type = 5;</code>
+   */
+  org.jetbrains.kotlin.backend.common.serialization.proto.IrTypeIndex getExpandedType();
+
+  /**
+   * <code>required bool is_actual = 6;</code>
+   */
+  boolean hasIsActual();
+  /**
+   * <code>required bool is_actual = 6;</code>
+   */
+  boolean getIsActual();
+}
\ No newline at end of file
diff --git a/compiler/ir/serialization.js/src/js.proto b/compiler/ir/serialization.js/src/js.proto
index e31a3cce3db..b307fb32063 100644
--- a/compiler/ir/serialization.js/src/js.proto
+++ b/compiler/ir/serialization.js/src/js.proto
@@ -110,6 +110,11 @@ extend org.jetbrains.kotlin.metadata.PackageFragment {
   optional Files package_fragment_files = 130;
 }
 
+extend org.jetbrains.kotlin.metadata.TypeAlias {
+  // TODO repeated org.jetbrains.kotlin.metadata.Annotation type_alias_annotation = 130;
+  optional DescriptorUniqId type_alias_uniq_id = 131;
+}
+
 message Classes {
   // id in StringTable
   repeated int32 class_name = 1 [packed = true];
diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDescriptorUniqIdAware.kt b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDescriptorUniqIdAware.kt
index 19e073dd097..69a85511437 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDescriptorUniqIdAware.kt
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDescriptorUniqIdAware.kt
@@ -18,6 +18,7 @@ object JsDescriptorUniqIdAware: DescriptorUniqIdAware {
         is DeserializedPropertyDescriptor -> this.proto.tryGetExtension(JsKlibMetadataProtoBuf.propertyUniqId)
         is DeserializedClassConstructorDescriptor -> this.proto.tryGetExtension(JsKlibMetadataProtoBuf.constructorUniqId)
         is DeserializedTypeParameterDescriptor -> this.proto.tryGetExtension(JsKlibMetadataProtoBuf.typeParamUniqId)
+        is DeserializedTypeAliasDescriptor -> this.proto.tryGetExtension(JsKlibMetadataProtoBuf.typeAliasUniqId)
         else -> null
     }?.index
 }
diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/metadata/JsKlibMetadataProtoBuf.java b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/metadata/JsKlibMetadataProtoBuf.java
index f3e23ac9028..d7a4e448469 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/metadata/JsKlibMetadataProtoBuf.java
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/metadata/JsKlibMetadataProtoBuf.java
@@ -1,5 +1,5 @@
 // Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: compiler/ir/backend.js/src/js.proto
+// source: compiler/ir/serialization.js/src/js.proto
 
 package org.jetbrains.kotlin.ir.backend.js.lower.serialization.metadata;
 
@@ -30,6 +30,7 @@ public final class JsKlibMetadataProtoBuf {
     registry.add(org.jetbrains.kotlin.ir.backend.js.lower.serialization.metadata.JsKlibMetadataProtoBuf.typeParameterAnnotation);
     registry.add(org.jetbrains.kotlin.ir.backend.js.lower.serialization.metadata.JsKlibMetadataProtoBuf.typeParamUniqId);
     registry.add(org.jetbrains.kotlin.ir.backend.js.lower.serialization.metadata.JsKlibMetadataProtoBuf.packageFragmentFiles);
+    registry.add(org.jetbrains.kotlin.ir.backend.js.lower.serialization.metadata.JsKlibMetadataProtoBuf.typeAliasUniqId);
   }
   public interface HeaderOrBuilder extends
       // @@protoc_insertion_point(interface_extends:org.jetbrains.kotlin.ir.backend.js.lower.serialization.metadata.Header)
@@ -4215,6 +4216,26 @@ public final class JsKlibMetadataProtoBuf {
         130,
         org.jetbrains.kotlin.protobuf.WireFormat.FieldType.MESSAGE,
         org.jetbrains.kotlin.ir.backend.js.lower.serialization.metadata.JsKlibMetadataProtoBuf.Files.class);
+  public static final int TYPE_ALIAS_UNIQ_ID_FIELD_NUMBER = 131;
+  /**
+   * <code>extend .org.jetbrains.kotlin.metadata.TypeAlias { ... }</code>
+   *
+   * <pre>
+   * TODO repeated org.jetbrains.kotlin.metadata.Annotation type_alias_annotation = 130;
+   * </pre>
+   */
+  public static final
+    org.jetbrains.kotlin.protobuf.GeneratedMessageLite.GeneratedExtension<
+      org.jetbrains.kotlin.metadata.ProtoBuf.TypeAlias,
+      org.jetbrains.kotlin.ir.backend.js.lower.serialization.metadata.JsKlibMetadataProtoBuf.DescriptorUniqId> typeAliasUniqId = org.jetbrains.kotlin.protobuf.GeneratedMessageLite
+          .newSingularGeneratedExtension(
+        org.jetbrains.kotlin.metadata.ProtoBuf.TypeAlias.getDefaultInstance(),
+        org.jetbrains.kotlin.ir.backend.js.lower.serialization.metadata.JsKlibMetadataProtoBuf.DescriptorUniqId.getDefaultInstance(),
+        org.jetbrains.kotlin.ir.backend.js.lower.serialization.metadata.JsKlibMetadataProtoBuf.DescriptorUniqId.getDefaultInstance(),
+        null,
+        131,
+        org.jetbrains.kotlin.protobuf.WireFormat.FieldType.MESSAGE,
+        org.jetbrains.kotlin.ir.backend.js.lower.serialization.metadata.JsKlibMetadataProtoBuf.DescriptorUniqId.class);
 
   static {
   }
diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/metadata/JsKlibMetadataSerializerExtension.kt b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/metadata/JsKlibMetadataSerializerExtension.kt
index f9447078d4d..93071843b5c 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/metadata/JsKlibMetadataSerializerExtension.kt
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/metadata/JsKlibMetadataSerializerExtension.kt
@@ -41,6 +41,11 @@ class JsKlibMetadataSerializerExtension(
         super.serializeTypeParameter(typeParameter, proto)
     }
 
+    override fun serializeTypeAlias(typeAlias: TypeAliasDescriptor, proto: ProtoBuf.TypeAlias.Builder) {
+        uniqId(typeAlias)?.let { proto.setExtension(JsKlibMetadataProtoBuf.typeAliasUniqId, it) }
+        super.serializeTypeAlias(typeAlias, proto)
+    }
+
     override fun serializeValueParameter(descriptor: ValueParameterDescriptor, proto: ProtoBuf.ValueParameter.Builder) {
         uniqId(descriptor)?.let { proto.setExtension(JsKlibMetadataProtoBuf.valueParamUniqId, it) }
         super.serializeValueParameter(descriptor, proto)
diff --git a/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt b/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt
index 3ab1e6b754f..f8adc936978 100644
--- a/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt
+++ b/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt
@@ -452,6 +452,8 @@ class DescriptorSerializer private constructor(
             builder.addAnnotation(extension.annotationSerializer.serializeAnnotation(annotation))
         }
 
+        extension.serializeTypeAlias(descriptor, builder)
+
         return builder
     }
 
diff --git a/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtension.kt b/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtension.kt
index decb6fda6f6..b5fc8131916 100644
--- a/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtension.kt
+++ b/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtension.kt
@@ -83,6 +83,9 @@ abstract class SerializerExtension {
     open fun serializeTypeParameter(typeParameter: TypeParameterDescriptor, proto: ProtoBuf.TypeParameter.Builder) {
     }
 
+    open fun serializeTypeAlias(typeAlias: TypeAliasDescriptor, proto: ProtoBuf.TypeAlias.Builder) {
+    }
+
     open fun serializeErrorType(type: KotlinType, builder: ProtoBuf.Type.Builder) {
         throw IllegalStateException("Cannot serialize error type: $type")
     }
diff --git a/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtensionBase.kt b/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtensionBase.kt
index a68d70e57f6..8a364ae22e6 100644
--- a/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtensionBase.kt
+++ b/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtensionBase.kt
@@ -106,4 +106,10 @@ abstract class KotlinSerializerExtensionBase(private val protocol: SerializerExt
             proto.addExtension(protocol.typeParameterAnnotation, annotationSerializer.serializeAnnotation(annotation))
         }
     }
+
+    override fun serializeTypeAlias(typeAlias: TypeAliasDescriptor, proto: ProtoBuf.TypeAlias.Builder) {
+        // TODO serialize annotations on type aliases?
+        // (this requires more extensive protobuf scheme modifications)
+    }
+
 }
diff --git a/generators/tests/org/jetbrains/kotlin/generators/protobuf/GenerateProtoBuf.kt b/generators/tests/org/jetbrains/kotlin/generators/protobuf/GenerateProtoBuf.kt
index 63a2b121b11..2b84a6400c7 100644
--- a/generators/tests/org/jetbrains/kotlin/generators/protobuf/GenerateProtoBuf.kt
+++ b/generators/tests/org/jetbrains/kotlin/generators/protobuf/GenerateProtoBuf.kt
@@ -59,7 +59,11 @@ val PROTO_PATHS: List<ProtoPath> = listOf(
     ProtoPath("core/metadata.jvm/src/jvm_metadata.proto"),
     ProtoPath("core/metadata.jvm/src/jvm_module.proto"),
     ProtoPath("build-common/src/java_descriptors.proto"),
+
+    // TODO drop this scheme, 'compiler/ir/serialization.js/src/js.proto' is the actual one
     ProtoPath("compiler/ir/backend.js/src/js.proto", false),
+
+    ProtoPath("compiler/ir/serialization.js/src/js.proto", false),
     ProtoPath("compiler/ir/serialization.common/src/KotlinIr.proto", false)
 )