diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/AbstractSuspendFunctionsLowering.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/AbstractSuspendFunctionsLowering.kt
index b1883332329..499d147fa20 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/AbstractSuspendFunctionsLowering.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/AbstractSuspendFunctionsLowering.kt
@@ -7,24 +7,21 @@ package org.jetbrains.kotlin.backend.common.lower
 
 import org.jetbrains.kotlin.backend.common.*
 import org.jetbrains.kotlin.backend.common.ir.*
-import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.builders.*
+import org.jetbrains.kotlin.ir.builders.declarations.buildClass
 import org.jetbrains.kotlin.ir.builders.declarations.buildConstructor
 import org.jetbrains.kotlin.ir.builders.declarations.buildFun
 import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.declarations.impl.IrClassImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrFieldImpl
-import org.jetbrains.kotlin.ir.descriptors.WrappedClassDescriptor
 import org.jetbrains.kotlin.ir.descriptors.WrappedFieldDescriptor
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrInstanceInitializerCallImpl
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
-import org.jetbrains.kotlin.ir.symbols.impl.IrClassSymbolImpl
 import org.jetbrains.kotlin.ir.symbols.impl.IrFieldSymbolImpl
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.classifierOrFail
@@ -271,31 +268,25 @@ abstract class AbstractSuspendFunctionsLowering<C : CommonBackendContext>(val co
     )
 
     private inner class CoroutineBuilder(val irFunction: IrFunction, val functionReference: IrFunctionReference?) {
-
-        private val startOffset = irFunction.startOffset
-        private val endOffset = irFunction.endOffset
         private val functionParameters = irFunction.explicitParameters
         private val boundFunctionParameters = functionReference?.getArgumentsWithIr()?.map { it.first }
         private val unboundFunctionParameters = boundFunctionParameters?.let { functionParameters - it }
 
-        private val coroutineClass: IrClass = WrappedClassDescriptor().let { d ->
-            IrClassImpl(
-                startOffset, endOffset,
-                DECLARATION_ORIGIN_COROUTINE_IMPL,
-                IrClassSymbolImpl(d),
-                nameForCoroutineClass(irFunction),
-                ClassKind.CLASS,
-                irFunction.visibility,
-                Modality.FINAL
-            ).apply {
-                d.bind(this)
+        private val coroutineClass: IrClass =
+            buildClass {
+                startOffset = irFunction.startOffset
+                endOffset = irFunction.endOffset
+                origin = DECLARATION_ORIGIN_COROUTINE_IMPL
+                name = nameForCoroutineClass(irFunction)
+                visibility = irFunction.visibility
+            }.apply {
                 parent = irFunction.parent
                 createParameterDeclarations()
                 typeParameters = irFunction.typeParameters.map { typeParam ->
                     typeParam.copyToWithoutSuperTypes(this).apply { superTypes += typeParam.superTypes }
                 }
             }
-        }
+
         private val coroutineClassThis = coroutineClass.thisReceiver!!
 
         private val continuationType = continuationClassSymbol.typeWith(irFunction.returnType)
diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/ir/builders/declarations/declarationBuilders.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/ir/builders/declarations/declarationBuilders.kt
index cb77575ea36..c4d0f7e608d 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/ir/builders/declarations/declarationBuilders.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/ir/builders/declarations/declarationBuilders.kt
@@ -19,14 +19,14 @@ import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.serialization.deserialization.descriptors.DescriptorWithContainerSource
 import org.jetbrains.kotlin.types.Variance
 
-fun IrClassBuilder.buildClass(): IrClass {
+@PublishedApi
+internal fun IrClassBuilder.buildClass(): IrClass {
     val wrappedDescriptor = WrappedClassDescriptor()
     return IrClassImpl(
         startOffset, endOffset, origin,
         IrClassSymbolImpl(wrappedDescriptor),
         name, kind, visibility, modality,
-        isCompanion = isCompanion, isInner = isInner, isData = isData, isExternal = isExternal,
-        isInline = isInline, isExpect = isExpect, isFun = isFun
+        isCompanion, isInner, isData, isExternal, isInline, isExpect, isFun
     ).also {
         wrappedDescriptor.bind(it)
     }
@@ -38,7 +38,6 @@ inline fun buildClass(builder: IrClassBuilder.() -> Unit) =
         buildClass()
     }
 
-
 fun IrFieldBuilder.buildField(): IrField {
     val wrappedDescriptor = WrappedFieldDescriptor()
     return IrFieldImpl(
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/AbstractSuspendFunctionsLowering.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/AbstractSuspendFunctionsLowering.kt
index c5e0ce1ae0a..7662add1f8e 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/AbstractSuspendFunctionsLowering.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/AbstractSuspendFunctionsLowering.kt
@@ -8,24 +8,21 @@ package org.jetbrains.kotlin.ir.backend.js.lower.coroutines
 import org.jetbrains.kotlin.backend.common.*
 import org.jetbrains.kotlin.backend.common.ir.*
 import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
-import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.backend.js.lower.CallableReferenceLowering
 import org.jetbrains.kotlin.ir.builders.*
+import org.jetbrains.kotlin.ir.builders.declarations.buildClass
 import org.jetbrains.kotlin.ir.builders.declarations.buildConstructor
 import org.jetbrains.kotlin.ir.builders.declarations.buildFun
 import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.declarations.impl.IrClassImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrFieldImpl
-import org.jetbrains.kotlin.ir.descriptors.WrappedClassDescriptor
 import org.jetbrains.kotlin.ir.descriptors.WrappedFieldDescriptor
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrInstanceInitializerCallImpl
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
-import org.jetbrains.kotlin.ir.symbols.impl.IrClassSymbolImpl
 import org.jetbrains.kotlin.ir.symbols.impl.IrFieldSymbolImpl
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.classifierOrFail
@@ -224,17 +221,14 @@ abstract class AbstractSuspendFunctionsLowering<C : CommonBackendContext>(val co
             else buildNewCoroutineClass(function)
         }
 
-        private fun buildNewCoroutineClass(function: IrSimpleFunction): IrClass = WrappedClassDescriptor().let { d ->
-            IrClassImpl(
-                startOffset, endOffset,
-                DECLARATION_ORIGIN_COROUTINE_IMPL,
-                IrClassSymbolImpl(d),
-                nameForCoroutineClass(function),
-                ClassKind.CLASS,
-                function.visibility,
-                Modality.FINAL
-            ).apply {
-                d.bind(this)
+        private fun buildNewCoroutineClass(function: IrSimpleFunction): IrClass =
+            buildClass {
+                startOffset = function.startOffset
+                endOffset = function.endOffset
+                origin = DECLARATION_ORIGIN_COROUTINE_IMPL
+                name = nameForCoroutineClass(function)
+                visibility = function.visibility
+            }.apply {
                 parent = function.parent
                 createParameterDeclarations()
                 typeParameters = function.typeParameters.map { typeParam ->
@@ -242,7 +236,6 @@ abstract class AbstractSuspendFunctionsLowering<C : CommonBackendContext>(val co
                     typeParam.copyToWithoutSuperTypes(this).apply { superTypes += typeParam.superTypes }
                 }
             }
-        }
 
         private fun buildConstructor(): IrConstructor {
             if (isSuspendLambda) {
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/JvmDeclarationFactory.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/JvmDeclarationFactory.kt
index c180fc03304..8efbcc3d5f9 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/JvmDeclarationFactory.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/JvmDeclarationFactory.kt
@@ -17,20 +17,13 @@ import org.jetbrains.kotlin.builtins.CompanionObjectMapping.isMappedIntrinsicCom
 import org.jetbrains.kotlin.codegen.AsmUtil
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
-import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
-import org.jetbrains.kotlin.ir.builders.declarations.buildConstructor
-import org.jetbrains.kotlin.ir.builders.declarations.buildField
-import org.jetbrains.kotlin.ir.builders.declarations.buildFun
-import org.jetbrains.kotlin.ir.builders.declarations.buildValueParameter
+import org.jetbrains.kotlin.ir.builders.declarations.*
 import org.jetbrains.kotlin.ir.builders.irCall
 import org.jetbrains.kotlin.ir.builders.setSourceRange
 import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.declarations.impl.IrClassImpl
-import org.jetbrains.kotlin.ir.descriptors.WrappedClassDescriptor
 import org.jetbrains.kotlin.ir.expressions.IrExpressionBody
-import org.jetbrains.kotlin.ir.symbols.impl.IrClassSymbolImpl
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.load.java.JavaVisibilities
 import org.jetbrains.kotlin.load.java.JvmAbi
@@ -245,17 +238,12 @@ class JvmDeclarationFactory(
 
     fun getDefaultImplsClass(interfaceClass: IrClass): IrClass =
         defaultImplsClasses.getOrPut(interfaceClass) {
-            val descriptor = WrappedClassDescriptor()
-            IrClassImpl(
-                interfaceClass.startOffset, interfaceClass.endOffset,
-                JvmLoweredDeclarationOrigin.DEFAULT_IMPLS,
-                IrClassSymbolImpl(descriptor),
-                Name.identifier(JvmAbi.DEFAULT_IMPLS_CLASS_NAME),
-                ClassKind.CLASS,
-                Visibilities.PUBLIC,
-                Modality.FINAL
-            ).apply {
-                descriptor.bind(this)
+            buildClass {
+                startOffset = interfaceClass.startOffset
+                endOffset = interfaceClass.endOffset
+                origin = JvmLoweredDeclarationOrigin.DEFAULT_IMPLS
+                name = Name.identifier(JvmAbi.DEFAULT_IMPLS_CLASS_NAME)
+            }.apply {
                 parent = interfaceClass
                 createImplicitParameterDeclarationWithWrappedDescriptor()
             }