diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/MultifileClassPartCodegen.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/MultifileClassPartCodegen.kt
index 5e80c411eff..8a89708bde4 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/MultifileClassPartCodegen.kt
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/MultifileClassPartCodegen.kt
@@ -176,7 +176,7 @@ class MultifileClassPartCodegen(
         }
 
         val serializer = DescriptorSerializer.createTopLevel(JvmSerializerExtension(v.serializationBindings, state))
-        val packageProto = serializer.packagePartProto(members).build()
+        val packageProto = serializer.packagePartProto(packageFragment.fqName, members).build()
 
         val extraFlags = if (shouldGeneratePartHierarchy) JvmAnnotationNames.METADATA_MULTIFILE_PARTS_INHERIT_FLAG else 0
 
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/PackagePartCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/PackagePartCodegen.java
index a313d7211bb..a0c99f338a7 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/PackagePartCodegen.java
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/PackagePartCodegen.java
@@ -129,7 +129,7 @@ public class PackagePartCodegen extends MemberCodegen<KtFile> {
 
         final DescriptorSerializer serializer =
                 DescriptorSerializer.createTopLevel(new JvmSerializerExtension(v.getSerializationBindings(), state));
-        final ProtoBuf.Package packageProto = serializer.packagePartProto(members).build();
+        final ProtoBuf.Package packageProto = serializer.packagePartProto(element.getPackageFqName(), members).build();
 
         WriteAnnotationUtilKt.writeKotlinMetadata(v, state, KotlinClassHeader.Kind.FILE_FACADE, 0, new Function1<AnnotationVisitor, Unit>() {
             @Override
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/serialization/JvmSerializerExtension.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/serialization/JvmSerializerExtension.java
index a9a64e58fd9..3c06a2c0678 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/serialization/JvmSerializerExtension.java
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/serialization/JvmSerializerExtension.java
@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.load.java.lazy.types.RawTypeImpl;
 import org.jetbrains.kotlin.load.kotlin.JavaFlexibleTypeDeserializer;
 import org.jetbrains.kotlin.load.kotlin.TypeSignatureMappingKt;
 import org.jetbrains.kotlin.name.ClassId;
+import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.serialization.AnnotationSerializer;
 import org.jetbrains.kotlin.serialization.ProtoBuf;
 import org.jetbrains.kotlin.serialization.SerializerExtension;
@@ -77,7 +78,7 @@ public class JvmSerializerExtension extends SerializerExtension {
     }
 
     @Override
-    public void serializePackage(@NotNull ProtoBuf.Package.Builder proto) {
+    public void serializePackage(@NotNull FqName packageFqName, @NotNull ProtoBuf.Package.Builder proto) {
         if (!moduleName.equals(JvmAbi.DEFAULT_MODULE_NAME)) {
             proto.setExtension(JvmProtoBuf.packageModuleName, stringTable.getStringIndex(moduleName));
         }
diff --git a/compiler/builtins-serializer/src/org/jetbrains/kotlin/serialization/MetadataSerializer.kt b/compiler/builtins-serializer/src/org/jetbrains/kotlin/serialization/MetadataSerializer.kt
index e651dad1c8a..1198e765a8f 100644
--- a/compiler/builtins-serializer/src/org/jetbrains/kotlin/serialization/MetadataSerializer.kt
+++ b/compiler/builtins-serializer/src/org/jetbrains/kotlin/serialization/MetadataSerializer.kt
@@ -141,11 +141,11 @@ open class MetadataSerializer(private val dependOnOldBuiltIns: Boolean) {
     protected inner class PackageSerializer(
             private val classes: Collection<DeclarationDescriptor>,
             private val members: Collection<DeclarationDescriptor>,
-            packageFqName: FqName,
+            private val packageFqName: FqName,
             private val destFile: File
     ) {
         private val proto = ProtoBuf.PackageFragment.newBuilder()
-        private val extension = BuiltInsSerializerExtension(packageFqName)
+        private val extension = BuiltInsSerializerExtension()
 
         fun run() {
             serializeClasses(classes)
@@ -170,7 +170,7 @@ open class MetadataSerializer(private val dependOnOldBuiltIns: Boolean) {
         }
 
         private fun serializeMembers(members: Collection<DeclarationDescriptor>) {
-            proto.`package` = DescriptorSerializer.createTopLevel(extension).packagePartProto(members).build()
+            proto.`package` = DescriptorSerializer.createTopLevel(extension).packagePartProto(packageFqName, members).build()
         }
 
         private fun serializeStringTable() {
diff --git a/compiler/builtins-serializer/src/org/jetbrains/kotlin/serialization/builtins/BuiltInsSerializerExtension.kt b/compiler/builtins-serializer/src/org/jetbrains/kotlin/serialization/builtins/BuiltInsSerializerExtension.kt
index 1fec80268b2..1b984dbf6fb 100644
--- a/compiler/builtins-serializer/src/org/jetbrains/kotlin/serialization/builtins/BuiltInsSerializerExtension.kt
+++ b/compiler/builtins-serializer/src/org/jetbrains/kotlin/serialization/builtins/BuiltInsSerializerExtension.kt
@@ -17,9 +17,8 @@
 package org.jetbrains.kotlin.serialization.builtins
 
 import org.jetbrains.kotlin.builtins.BuiltInSerializerProtocol
-import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.serialization.KotlinSerializerExtensionBase
 
-class BuiltInsSerializerExtension(packageFqName: FqName) : KotlinSerializerExtensionBase(BuiltInSerializerProtocol, packageFqName) {
+class BuiltInsSerializerExtension : KotlinSerializerExtensionBase(BuiltInSerializerProtocol) {
     override fun shouldUseTypeTable(): Boolean = true
 }
diff --git a/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt b/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt
index 4564f7764d5..e014a5403e6 100644
--- a/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt
+++ b/compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt
@@ -17,20 +17,18 @@
 package org.jetbrains.kotlin.serialization
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
-import org.jetbrains.kotlin.builtins.functions.FunctionClassDescriptor
-import org.jetbrains.kotlin.builtins.getFunctionalClassKind
 import org.jetbrains.kotlin.builtins.isSuspendFunctionType
 import org.jetbrains.kotlin.builtins.transformSuspendFunctionToRuntimeFunctionType
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.Annotated
+import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.protobuf.MessageLite
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.DescriptorUtils.isEnumEntry
 import org.jetbrains.kotlin.resolve.MemberComparator
 import org.jetbrains.kotlin.resolve.constants.NullValue
-import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
 import org.jetbrains.kotlin.serialization.deserialization.descriptors.SinceKotlinInfo
 import org.jetbrains.kotlin.types.*
 import org.jetbrains.kotlin.types.typeUtil.contains
@@ -543,7 +541,7 @@ class DescriptorSerializer private constructor(
         return builder
     }
 
-    fun packagePartProto(members: Collection<DeclarationDescriptor>): ProtoBuf.Package.Builder {
+    fun packagePartProto(packageFqName: FqName, members: Collection<DeclarationDescriptor>): ProtoBuf.Package.Builder {
         val builder = ProtoBuf.Package.newBuilder()
 
         for (declaration in sort(members)) {
@@ -564,7 +562,7 @@ class DescriptorSerializer private constructor(
             builder.sinceKotlinInfoTable = sinceKotlinInfoProto
         }
 
-        extension.serializePackage(builder)
+        extension.serializePackage(packageFqName, 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 5f38b48d0f0..9da320b774f 100644
--- a/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtension.kt
+++ b/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtension.kt
@@ -17,6 +17,7 @@
 package org.jetbrains.kotlin.serialization
 
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.types.FlexibleType
 import org.jetbrains.kotlin.types.KotlinType
 
@@ -30,7 +31,7 @@ abstract class SerializerExtension {
     open fun serializeClass(descriptor: ClassDescriptor, proto: ProtoBuf.Class.Builder) {
     }
 
-    open fun serializePackage(proto: ProtoBuf.Package.Builder) {
+    open fun serializePackage(packageFqName: FqName, proto: ProtoBuf.Package.Builder) {
     }
 
     open fun serializeConstructor(descriptor: ConstructorDescriptor, proto: ProtoBuf.Constructor.Builder) {
diff --git a/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtensionBase.kt b/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtensionBase.kt
index d38acaf521c..d827400c37e 100644
--- a/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtensionBase.kt
+++ b/compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtensionBase.kt
@@ -21,10 +21,7 @@ import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.resolve.constants.NullValue
 import org.jetbrains.kotlin.types.KotlinType
 
-open class KotlinSerializerExtensionBase(
-        private val protocol: SerializerExtensionProtocol,
-        private val packageFqName: FqName
-) : SerializerExtension() {
+open class KotlinSerializerExtensionBase(private val protocol: SerializerExtensionProtocol) : SerializerExtension() {
     override val stringTable = StringTableImpl()
 
     override fun serializeClass(descriptor: ClassDescriptor, proto: ProtoBuf.Class.Builder) {
@@ -33,7 +30,7 @@ open class KotlinSerializerExtensionBase(
         }
     }
 
-    override fun serializePackage(proto: ProtoBuf.Package.Builder) {
+    override fun serializePackage(packageFqName: FqName, proto: ProtoBuf.Package.Builder) {
         proto.setExtension(protocol.packageFqName, stringTable.getPackageFqNameIndex(packageFqName))
     }
 
diff --git a/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt b/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt
index 8aa23ba4c16..5e96fcb641e 100644
--- a/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt
+++ b/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt
@@ -93,7 +93,7 @@ object KotlinJavascriptSerializationUtil {
         val skip: (DeclarationDescriptor) -> Boolean = { DescriptorUtils.getContainingModule(it) != module || (it is MemberDescriptor && it.isHeader) }
 
         val fileRegistry = KotlinFileRegistry()
-        val serializerExtension = KotlinJavascriptSerializerExtension(fileRegistry, fqName)
+        val serializerExtension = KotlinJavascriptSerializerExtension(fileRegistry)
         val serializer = DescriptorSerializer.createTopLevel(serializerExtension)
 
         val classDescriptors = DescriptorSerializer.sort(
@@ -123,7 +123,7 @@ object KotlinJavascriptSerializationUtil {
         val members = fragments
                 .flatMap { fragment -> DescriptorUtils.getAllDescriptors(fragment.getMemberScope()) }
                 .filterNot(skip)
-        builder.`package` = serializer.packagePartProto(members).build()
+        builder.`package` = serializer.packagePartProto(fqName, members).build()
 
         builder.setExtension(
                 JsProtoBuf.packageFragmentFiles,
diff --git a/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializerExtension.kt b/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializerExtension.kt
index b3de85cd478..24aef0aa4b8 100644
--- a/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializerExtension.kt
+++ b/js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializerExtension.kt
@@ -29,9 +29,8 @@ import org.jetbrains.kotlin.serialization.SerializerExtensionProtocol
 import org.jetbrains.kotlin.types.FlexibleType
 
 class KotlinJavascriptSerializerExtension(
-        private val fileRegistry: KotlinFileRegistry,
-        packageFqName: FqName
-) : KotlinSerializerExtensionBase(JsSerializerProtocol, packageFqName) {
+        private val fileRegistry: KotlinFileRegistry
+) : KotlinSerializerExtensionBase(JsSerializerProtocol) {
     override val stringTable = JavaScriptStringTable()
 
     override fun serializeFlexibleType(flexibleType: FlexibleType, lowerProto: ProtoBuf.Type.Builder, upperProto: ProtoBuf.Type.Builder) {