diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Boxing.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Boxing.kt
index d76f785f14a..f0ef3f4e642 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Boxing.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Boxing.kt
@@ -14,6 +14,7 @@ import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.ir.declarations.IrClass
 import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
+import org.jetbrains.kotlin.ir.declarations.IrFile
 import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.declarations.impl.IrFunctionImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrValueParameterImpl
@@ -45,6 +46,7 @@ private fun KonanSymbols.getTypeConversionImpl(
 
 internal val Context.getBoxFunction: (IrClass) -> IrSimpleFunction by Context.lazyMapMember { inlinedClass ->
     assert(inlinedClass.isUsedAsBoxClass())
+    assert(inlinedClass.parent is IrFile) { "Expected top level inline class" }
 
     val symbols = ir.symbols
 
@@ -63,7 +65,7 @@ internal val Context.getBoxFunction: (IrClass) -> IrSimpleFunction by Context.la
             startOffset, endOffset,
             IrDeclarationOrigin.DEFINED,
             IrSimpleFunctionSymbolImpl(descriptor),
-            Name.special("<box>"),
+            Name.special("<${inlinedClass.name}-box>"),
             Visibilities.PUBLIC,
             Modality.FINAL,
             returnType,
@@ -89,12 +91,13 @@ internal val Context.getBoxFunction: (IrClass) -> IrSimpleFunction by Context.la
             }
         })
         descriptor.bind(function)
-        function.parent = inlinedClass
+        function.parent = inlinedClass.getContainingFile()!!
     }
 }
 
 internal val Context.getUnboxFunction: (IrClass) -> IrSimpleFunction by Context.lazyMapMember { inlinedClass ->
     assert(inlinedClass.isUsedAsBoxClass())
+    assert(inlinedClass.parent is IrFile) { "Expected top level inline class" }
 
     val symbols = ir.symbols
 
@@ -113,7 +116,7 @@ internal val Context.getUnboxFunction: (IrClass) -> IrSimpleFunction by Context.
             startOffset, endOffset,
             IrDeclarationOrigin.DEFINED,
             IrSimpleFunctionSymbolImpl(descriptor),
-            Name.special("<unbox>"),
+            Name.special("<${inlinedClass.name}-unbox>"),
             Visibilities.PUBLIC,
             Modality.FINAL,
             returnType,
@@ -139,7 +142,7 @@ internal val Context.getUnboxFunction: (IrClass) -> IrSimpleFunction by Context.
             }
         })
         descriptor.bind(function)
-        function.parent = inlinedClass
+        function.parent = inlinedClass.getContainingFile()!!
     }
 }
 
diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/Autoboxing.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/Autoboxing.kt
index e36f3044fd0..cb72d727394 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/Autoboxing.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/Autoboxing.kt
@@ -17,7 +17,6 @@ import org.jetbrains.kotlin.backend.konan.descriptors.target
 import org.jetbrains.kotlin.backend.konan.ir.*
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
-import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.builders.*
 import org.jetbrains.kotlin.ir.declarations.*
@@ -46,7 +45,7 @@ internal class Autoboxing(val context: Context) : FileLoweringPass {
 
     override fun lower(irFile: IrFile) {
         irFile.transformChildrenVoid(transformer)
-        irFile.transformChildrenVoid(InlineClassTransformer(context))
+        irFile.transform(InlineClassTransformer(context), data = null)
     }
 
 }
@@ -213,6 +212,15 @@ private class InlineClassTransformer(private val context: Context) : IrBuildingT
     private val symbols = context.ir.symbols
     private val irBuiltIns = context.irBuiltIns
 
+    private val builtBoxUnboxFunctions = mutableListOf<IrFunction>()
+
+    override fun visitFile(declaration: IrFile): IrFile {
+        declaration.transformChildrenVoid(this)
+        declaration.declarations.addAll(builtBoxUnboxFunctions)
+        builtBoxUnboxFunctions.clear()
+        return declaration
+    }
+
     override fun visitClass(declaration: IrClass): IrStatement {
         super.visitClass(declaration)
 
@@ -341,7 +349,7 @@ private class InlineClassTransformer(private val context: Context) : IrBuildingT
             +irReturn(irGet(box))
         }
 
-        irClass.declarations += function
+        builtBoxUnboxFunctions += function
     }
 
     private fun IrBuilderWithScope.irNullPointerOrReference(type: IrType): IrExpression =
@@ -367,7 +375,7 @@ private class InlineClassTransformer(private val context: Context) : IrBuildingT
             +irReturn(irGetField(irGet(boxParameter), getInlineClassBackingField(irClass)))
         }
 
-        irClass.declarations += function
+        builtBoxUnboxFunctions += function
     }
 
     private fun buildBoxField(declaration: IrClass) {
diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/DataFlowIR.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/DataFlowIR.kt
index 29f42bdb90c..2dafd7e9896 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/DataFlowIR.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/DataFlowIR.kt
@@ -642,7 +642,7 @@ internal object DataFlowIR {
         }
 
         private val IrFunction.isSpecial get() =
-            name.asString().let { it.startsWith("<bridge-") || it == "<box>" || it == "<unbox>" }
+            name.asString().let { it.startsWith("<bridge-") || it.endsWith("-box>") || it.endsWith("-unbox>") }
 
         private fun mapPropertyInitializer(irField: IrField): FunctionSymbol {
             functionMap[irField]?.let { return it }
diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/Devirtualization.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/Devirtualization.kt
index d9166bdb333..c362808ee3f 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/Devirtualization.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/Devirtualization.kt
@@ -1033,10 +1033,10 @@ internal object Devirtualization {
         }
     }
 
-    private val specialNames = listOf("<box>", "<unbox>")
+    private val specialNames = listOf("-box>", "-unbox>")
 
     // TODO: do it more reliably.
-    private fun IrExpression.isBoxOrUnboxCall() = (this is IrCall && symbol.owner.name.asString().let { specialNames.contains(it) })
+    private fun IrExpression.isBoxOrUnboxCall() = (this is IrCall && symbol.owner.name.asString().let { name -> specialNames.any { name.endsWith(it) } })
 
     private fun devirtualize(irModule: IrModuleFragment, context: Context, externalModulesDFG: ExternalModulesDFG,
                              devirtualizedCallSites: Map<IrCall, DevirtualizedCallSite>) {
@@ -1356,6 +1356,14 @@ internal object Devirtualization {
 
         irModule.transformChildrenVoid(object: IrElementTransformerVoid() {
 
+            fun IrFunction.getCoercedClass(): IrClassifierSymbol {
+                if (name.asString().endsWith("-box>"))
+                    return valueParameters[0].type.classifierOrFail
+                if (name.asString().endsWith("-unbox>"))
+                    return returnType.classifierOrFail
+                error("Unexpected coercion: ${this.dump()}")
+            }
+
             fun fold(expression: IrExpression, coercion: IrCall, cast: IrTypeOperatorCall?,
                      transformRecursively: Boolean): PossiblyFoldedExpression {
 
@@ -1367,11 +1375,11 @@ internal object Devirtualization {
                 fun IrElement.transformIfAsked() =
                         if (transformRecursively) this.transform(transformer, data = null) else this
 
-                val coercionDeclaringClass = coercion.symbol.owner.parentAsClass
+                val coercionDeclaringClass = coercion.symbol.owner.getCoercedClass()
                 if (expression.isBoxOrUnboxCall()) {
                     expression as IrCall
                     val result =
-                            if (coercionDeclaringClass == expression.symbol.owner.parentAsClass)
+                            if (coercionDeclaringClass == expression.symbol.owner.getCoercedClass())
                                 expression.getArguments().single().second
                             else expression