diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/InnerClassesLowering.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/InnerClassesLowering.kt
index b6204271665..daf55fae955 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/InnerClassesLowering.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/InnerClassesLowering.kt
@@ -20,7 +20,10 @@ import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
 import org.jetbrains.kotlin.ir.symbols.IrValueSymbol
-import org.jetbrains.kotlin.ir.util.*
+import org.jetbrains.kotlin.ir.util.createParameterDeclarations
+import org.jetbrains.kotlin.ir.util.defaultType
+import org.jetbrains.kotlin.ir.util.dump
+import org.jetbrains.kotlin.ir.util.transformFlat
 import org.jetbrains.kotlin.ir.visitors.*
 import org.jetbrains.kotlin.resolve.scopes.receivers.ImplicitClassReceiver
 import java.util.*
@@ -29,12 +32,9 @@ class InnerClassesLowering(val context: BackendContext) : ClassLoweringPass {
     object FIELD_FOR_OUTER_THIS : IrDeclarationOriginImpl("FIELD_FOR_OUTER_THIS")
 
     override fun lower(irClass: IrClass) {
-        TODO()
-//        InnerClassTransformer(irClass).lowerInnerClass()
+        InnerClassTransformer(irClass).lowerInnerClass()
     }
 
-    /*
-
     private inner class InnerClassTransformer(val irClass: IrClass) {
         lateinit var outerThisField: IrField
 
@@ -70,12 +70,14 @@ class InnerClassesLowering(val context: BackendContext) : ClassLoweringPass {
         }
 
         private fun createOuterThisField() {
+            val fieldSymbol = context.descriptorsFactory.getOuterThisFieldSymbol(irClass)
             irClass.declarations.add(
                 IrFieldImpl(
                     irClass.startOffset, irClass.endOffset,
                     FIELD_FOR_OUTER_THIS,
-                    context.descriptorsFactory.getOuterThisFieldSymbol(irClass)
-                ).also {
+                    fieldSymbol,
+                    irClass.defaultType
+                    ).also {
                     outerThisField = it
                 }
             )
@@ -100,7 +102,10 @@ class InnerClassesLowering(val context: BackendContext) : ClassLoweringPass {
                 irConstructor.origin, // TODO special origin for lowered inner class constructors?
                 newSymbol,
                 null
-            )
+            ).apply {
+                returnType = irConstructor.returnType
+            }
+
             loweredConstructor.createParameterDeclarations()
             val outerThisValueParameter = loweredConstructor.valueParameters[0].symbol
 
@@ -118,7 +123,8 @@ class InnerClassesLowering(val context: BackendContext) : ClassLoweringPass {
                     IrSetFieldImpl(
                         startOffset, endOffset, outerThisField.symbol,
                         IrGetValueImpl(startOffset, endOffset, irClass.thisReceiver!!.symbol),
-                        IrGetValueImpl(startOffset, endOffset, outerThisValueParameter)
+                        IrGetValueImpl(startOffset, endOffset, outerThisValueParameter),
+                        context.irBuiltIns.unitType
                     )
                 )
             } else {
@@ -169,7 +175,7 @@ class InnerClassesLowering(val context: BackendContext) : ClassLoweringPass {
                         }
 
                         val outerThisField = context.descriptorsFactory.getOuterThisFieldSymbol(innerClass)
-                        irThis = IrGetFieldImpl(startOffset, endOffset, outerThisField, irThis, origin)
+                        irThis = IrGetFieldImpl(startOffset, endOffset, outerThisField, innerClass.defaultType, irThis, origin)
 
                         val outer = innerClass.parent
                         innerClass = outer as? IrClass ?:
@@ -192,14 +198,10 @@ class InnerClassesLowering(val context: BackendContext) : ClassLoweringPass {
             return null
         }
     }
-
-    */
 }
 
 class InnerClassConstructorCallsLowering(val context: BackendContext) : BodyLoweringPass {
     override fun lower(irBody: IrBody) {
-        TODO()
-        /*
         irBody.transformChildrenVoid(object : IrElementTransformerVoid() {
             override fun visitCall(expression: IrCall): IrExpression {
                 expression.transformChildrenVoid(this)
@@ -211,8 +213,8 @@ class InnerClassConstructorCallsLowering(val context: BackendContext) : BodyLowe
 
                 val newCallee = context.descriptorsFactory.getInnerClassConstructorWithOuterThisParameter(callee.owner)
                 val newCall = IrCallImpl(
-                    expression.startOffset, expression.endOffset, newCallee, newCallee.descriptor,
-                    null, // TODO type arguments map
+                    expression.startOffset, expression.endOffset, expression.type, newCallee, newCallee.descriptor,
+                    0, // TODO type arguments map
                     expression.origin
                 )
 
@@ -233,7 +235,7 @@ class InnerClassConstructorCallsLowering(val context: BackendContext) : BodyLowe
 
                 val newCallee = context.descriptorsFactory.getInnerClassConstructorWithOuterThisParameter(classConstructor)
                 val newCall = IrDelegatingConstructorCallImpl(
-                    expression.startOffset, expression.endOffset, newCallee, newCallee.descriptor,
+                    expression.startOffset, expression.endOffset, expression.type, newCallee, newCallee.descriptor,
                     classConstructor.typeParameters.size
                 ).apply { copyTypeArgumentsFrom(expression) }
 
@@ -247,7 +249,6 @@ class InnerClassConstructorCallsLowering(val context: BackendContext) : BodyLowe
 
             // TODO callable references?
         })
-        */
     }
 }