diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/InlineClassDeclarationLowering.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/InlineClassDeclarationLowering.kt
index 264666d9484..b0ac5ec76df 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/InlineClassDeclarationLowering.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/InlineClassDeclarationLowering.kt
@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.backend.common.ClassLoweringPass
 import org.jetbrains.kotlin.backend.common.FileLoweringPass
 import org.jetbrains.kotlin.backend.common.descriptors.WrappedSimpleFunctionDescriptor
 import org.jetbrains.kotlin.backend.common.ir.copyTo
+import org.jetbrains.kotlin.backend.common.ir.copyTypeParametersFrom
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.builders.*
@@ -227,11 +228,6 @@ class InlineClassLowering(val context: BackendContext) {
 
     private fun createStaticBodilessMethod(function: IrFunction): IrSimpleFunction {
         val descriptor = WrappedSimpleFunctionDescriptor()
-        val returnType = when (function) {
-            is IrSimpleFunction -> function.returnType
-            is IrConstructor -> function.parentAsClass.defaultType
-            else -> error("Unknown function type")
-        }
 
         return IrFunctionImpl(
             function.startOffset,
@@ -241,7 +237,7 @@ class InlineClassLowering(val context: BackendContext) {
             function.name.toInlineClassImplementationName(),
             function.visibility,
             Modality.FINAL,
-            returnType,
+            function.returnType,
             function.isInline,
             function.isExternal,
             (function is IrSimpleFunction && function.isTailrec),
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/BridgesConstruction.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/BridgesConstruction.kt
index f0982c1645e..57a76106e61 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/BridgesConstruction.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/BridgesConstruction.kt
@@ -9,7 +9,7 @@ import org.jetbrains.kotlin.backend.common.ClassLoweringPass
 import org.jetbrains.kotlin.backend.common.bridges.FunctionHandle
 import org.jetbrains.kotlin.backend.common.bridges.generateBridges
 import org.jetbrains.kotlin.backend.common.ir.copyTo
-import org.jetbrains.kotlin.backend.common.ir.isStatic
+import org.jetbrains.kotlin.backend.common.ir.copyTypeParametersFrom
 import org.jetbrains.kotlin.backend.common.ir.isSuspend
 import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
 import org.jetbrains.kotlin.backend.common.lower.irBlockBody
@@ -120,7 +120,7 @@ class BridgesConstruction(val context: JsIrBackendContext) : ClassLoweringPass {
                 IrValueParameterImpl(startOffset, endOffset, origin, descriptor, type, varargElementType).also { it.parent = this@apply }
             }
             extensionReceiverParameter = bridge.extensionReceiverParameter?.copyTo(this)
-            typeParameters += bridge.typeParameters
+            copyTypeParametersFrom(bridge)
             valueParameters += bridge.valueParameters.map { p -> p.copyTo(this) }
             annotations += bridge.annotations
             overriddenSymbols.addAll(delegateTo.overriddenSymbols)
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ThrowableSuccessorsLowering.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ThrowableSuccessorsLowering.kt
index 6f703ecc403..d06f4e3e626 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ThrowableSuccessorsLowering.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ThrowableSuccessorsLowering.kt
@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.ir.backend.js.lower
 import org.jetbrains.kotlin.backend.common.FileLoweringPass
 import org.jetbrains.kotlin.backend.common.atMostOne
 import org.jetbrains.kotlin.backend.common.descriptors.WrappedPropertyDescriptor
+import org.jetbrains.kotlin.backend.common.ir.copyTo
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
@@ -183,7 +184,7 @@ class ThrowableSuccessorsLowering(context: JsIrBackendContext) : FileLoweringPas
             val function = JsIrBuilder.buildFunction(name, fakeAccessor.returnType, fakeAccessor.parent).apply {
                 overriddenSymbols += fakeAccessor.overriddenSymbols
                 correspondingProperty = fakeAccessor.correspondingProperty
-                dispatchReceiverParameter = fakeAccessor.dispatchReceiverParameter
+                dispatchReceiverParameter = fakeAccessor.dispatchReceiverParameter?.copyTo(this)
             }
 
             val thisReceiver = JsIrBuilder.buildGetValue(function.dispatchReceiverParameter!!.symbol)
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/SuspendFunctionsLowering.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/SuspendFunctionsLowering.kt
index 3cfb275b599..1ff9e3f9e09 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/SuspendFunctionsLowering.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/SuspendFunctionsLowering.kt
@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.ir.backend.js.lower.coroutines
 import org.jetbrains.kotlin.backend.common.*
 import org.jetbrains.kotlin.backend.common.descriptors.*
 import org.jetbrains.kotlin.backend.common.ir.copyParameterDeclarationsFrom
+import org.jetbrains.kotlin.backend.common.ir.copyTo
 import org.jetbrains.kotlin.backend.common.ir.isSuspend
 import org.jetbrains.kotlin.backend.common.lower.SymbolWithIrBuilder
 import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
@@ -507,8 +508,10 @@ internal class SuspendFunctionsLowering(val context: JsIrBackendContext): FileLo
                 descriptor.bind(declaration)
                 declaration.parent = coroutineClass
 
-                declaration.valueParameters += functionParameters.map {
-                    JsIrBuilder.buildValueParameter(it.name, it.index, it.type, it.origin).also { p -> p.parent = declaration }
+                declaration.valueParameters += functionParameters.mapIndexed { index: Int, parameter: IrValueParameter ->
+                    JsIrBuilder.buildValueParameter(parameter.name, index, parameter.type, parameter.origin).also { p ->
+                        p.parent = declaration
+                    }
                 }
                 declaration.valueParameters += JsIrBuilder.buildValueParameter(
                     completion.name,
@@ -637,7 +640,7 @@ internal class SuspendFunctionsLowering(val context: JsIrBackendContext): FileLo
                 descriptor.bind(declaration)
                 declaration.parent = coroutineClass
                 declaration.returnType = coroutineClass.defaultType
-                declaration.dispatchReceiverParameter = coroutineClassThis
+                declaration.dispatchReceiverParameter = coroutineClassThis.copyTo(declaration)
 
                 unboundArgs.mapIndexedTo(declaration.valueParameters) { i, p ->
                     JsIrBuilder.buildValueParameter(p.name, i, p.type, p.origin).also { it.parent = declaration }
@@ -656,7 +659,7 @@ internal class SuspendFunctionsLowering(val context: JsIrBackendContext): FileLo
                     declaration.overriddenSymbols += superFunctionDeclaration.symbol
                 }
 
-                val thisReceiver = coroutineClassThis
+                val thisReceiver = declaration.dispatchReceiverParameter!!
                 val irBuilder = context.createIrBuilder(symbol, irFunction.startOffset, irFunction.endOffset)
                 declaration.body = irBuilder.irBlockBody(irFunction.startOffset, irFunction.endOffset) {
                     +irReturn(
@@ -726,7 +729,7 @@ internal class SuspendFunctionsLowering(val context: JsIrBackendContext): FileLo
                 val resultSetter = context.coroutineImplResultSymbol.setter!!
                 val exceptionSetter = context.coroutineImplExceptionProperty.setter!!
 
-                val thisReceiver = coroutineClassThis
+                val thisReceiver = declaration.dispatchReceiverParameter!!
                 val irBuilder = context.createIrBuilder(symbol, irFunction.startOffset, irFunction.endOffset)
                 declaration.body = irBuilder.irBlockBody(irFunction.startOffset, irFunction.endOffset) {
                     val dispatchReceiverCall = irCall(createFunction).apply {
@@ -806,12 +809,12 @@ internal class SuspendFunctionsLowering(val context: JsIrBackendContext): FileLo
                     function.overriddenSymbols += doResumeFunction.symbol
                     function.parent = coroutineClass
                     function.returnType = context.irBuiltIns.anyNType
-                    function.dispatchReceiverParameter = coroutineClassThis
+                    function.dispatchReceiverParameter = coroutineClassThis.copyTo(function)
                     doResumeFunction.valueParameters.mapTo(function.valueParameters) {
                         JsIrBuilder.buildValueParameter(it.name, it.index, it.type, it.origin).also { p -> p.parent = function }
                     }
 
-                    val thisReceiver = JsIrBuilder.buildGetValue(coroutineClassThis.symbol)
+                    val thisReceiver = JsIrBuilder.buildGetValue(function.dispatchReceiverParameter!!.symbol)
                     suspendResult = JsIrBuilder.buildVar(
                         context.irBuiltIns.anyNType,
                         function,