diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/RemapTypes.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/RemapTypes.kt
new file mode 100644
index 00000000000..e8ba63b8cde
--- /dev/null
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/RemapTypes.kt
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.ir.util
+
+import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.expressions.IrExpression
+import org.jetbrains.kotlin.ir.expressions.IrTypeOperatorCall
+import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
+import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
+import org.jetbrains.kotlin.ir.visitors.acceptVoid
+
+// Modify IrElement in place, applying typeRemapper to all the IrType fields.
+fun IrElement.remapTypes(typeRemapper: TypeRemapper) {
+    acceptVoid(RemapTypesHelper(typeRemapper))
+}
+
+private class RemapTypesHelper(private val typeRemapper: TypeRemapper) : IrElementVisitorVoid {
+
+    override fun visitElement(element: IrElement) {
+        element.acceptChildrenVoid(this)
+    }
+
+    override fun visitExpression(expression: IrExpression) {
+        expression.type = typeRemapper.remapType(expression.type)
+        super.visitExpression(expression)
+    }
+
+    override fun visitValueParameter(declaration: IrValueParameter) {
+        declaration.type = typeRemapper.remapType(declaration.type)
+        super.visitValueParameter(declaration)
+    }
+
+    override fun visitVariable(declaration: IrVariable) {
+        declaration.type = typeRemapper.remapType(declaration.type)
+        super.visitVariable(declaration)
+    }
+
+    override fun visitFunction(declaration: IrFunction) {
+        declaration.returnType = typeRemapper.remapType(declaration.returnType)
+        super.visitFunction(declaration)
+    }
+
+    override fun visitField(declaration: IrField) {
+        declaration.type = typeRemapper.remapType(declaration.type)
+        super.visitField(declaration)
+    }
+
+    override fun visitLocalDelegatedProperty(declaration: IrLocalDelegatedProperty) {
+        declaration.type = typeRemapper.remapType(declaration.type)
+        super.visitLocalDelegatedProperty(declaration)
+    }
+
+    override fun visitTypeAlias(declaration: IrTypeAlias) {
+        declaration.expandedType = typeRemapper.remapType(declaration.expandedType)
+        super.visitTypeAlias(declaration)
+    }
+
+    override fun visitTypeOperator(expression: IrTypeOperatorCall) {
+        expression.typeOperand = typeRemapper.remapType(expression.typeOperand)
+        super.visitTypeOperator(expression)
+    }
+
+}
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