diff --git a/compiler/ir/ir.objcinterop/src/org/jetbrains/kotlin/ir/objcinterop/ObjCInterop.kt b/compiler/ir/ir.objcinterop/src/org/jetbrains/kotlin/ir/objcinterop/ObjCInterop.kt
index a753103fa5e..29907ff0edc 100644
--- a/compiler/ir/ir.objcinterop/src/org/jetbrains/kotlin/ir/objcinterop/ObjCInterop.kt
+++ b/compiler/ir/ir.objcinterop/src/org/jetbrains/kotlin/ir/objcinterop/ObjCInterop.kt
@@ -11,7 +11,11 @@ import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.descriptors.IrBasedClassConstructorDescriptor
 import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
+import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
+import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.classOrNull
+import org.jetbrains.kotlin.ir.types.classifierOrFail
+import org.jetbrains.kotlin.ir.types.superTypes
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.name.NativeForwardDeclarationKind
@@ -25,6 +29,7 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.parentsWithSelf
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeUtils
 import org.jetbrains.kotlin.types.typeUtil.supertypes
+import org.jetbrains.kotlin.utils.DFS
 
 private fun IrFunction.isFakeOverrideInProgressOfBuilding() = this is IrFunctionWithLateBinding && !isBound && isFakeOverride
 
@@ -54,6 +59,12 @@ private fun IrClass.selfOrAnySuperClass(pred: (IrClass) -> Boolean): Boolean {
 fun IrClass.isObjCClass() = this.packageFqName != interopPackageName &&
         selfOrAnySuperClass { it.hasEqualFqName(objCObjectFqName) }
 
+fun IrType.isObjCObjectType(): Boolean = DFS.ifAny(
+    /* nodes = */ listOf(this.classifierOrFail),
+    /* neighbors = */ { current -> current.superTypes().map { it.classifierOrFail } },
+    /* predicate = */ { (it as? IrClassSymbol)?.owner?.hasEqualFqName(objCObjectFqName) == true }
+)
+
 fun ClassDescriptor.isExternalObjCClass(): Boolean = this.isObjCClass() &&
         this.parentsWithSelf.filterIsInstance<ClassDescriptor>().any {
             it.annotations.findAnnotation(externalObjCClassFqName) != null
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/cgen/InteropIrUtils.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/cgen/InteropIrUtils.kt
index 6de5ab4bb1d..5ef98231bfc 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/cgen/InteropIrUtils.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/cgen/InteropIrUtils.kt
@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.konan.target.KonanTarget
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.ir.objcinterop.isObjCObjectType
 
 internal fun IrType.isCEnumType(): Boolean {
     if (isNullable()) return false
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ir/FakeIrUtils.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ir/FakeIrUtils.kt
deleted file mode 100644
index 7029ad45ac1..00000000000
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ir/FakeIrUtils.kt
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
- * Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
- * that can be found in the LICENSE file.
- */
-
-package org.jetbrains.kotlin.backend.konan.ir
-
-import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
-import org.jetbrains.kotlin.ir.objcinterop.isObjCObjectType
-import org.jetbrains.kotlin.ir.types.IrType
-import org.jetbrains.kotlin.ir.types.toKotlinType
-
-// This file contains some IR utilities which actually use descriptors.
-// TODO: port this code to IR.
-
-
-@OptIn(ObsoleteDescriptorBasedAPI::class)
-internal fun IrType.isObjCObjectType() = this.toKotlinType().isObjCObjectType()
-
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/DFGBuilder.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/DFGBuilder.kt
index b3066c53e66..829db6c3c65 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/DFGBuilder.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/optimizations/DFGBuilder.kt
@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
 import org.jetbrains.kotlin.ir.visitors.acceptVoid
 import org.jetbrains.kotlin.util.OperatorNameConventions
 import org.jetbrains.kotlin.backend.konan.llvm.*
+import org.jetbrains.kotlin.ir.objcinterop.isObjCObjectType
 
 internal class ExternalModulesDFG(val allTypes: List<DataFlowIR.Type.Declared>,
                                   val publicTypes: Map<Long, DataFlowIR.Type.Public>,