diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/CheckIrElementVisitor.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/CheckIrElementVisitor.kt
index 3f49ae2c736..f51f5fe34fd 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/CheckIrElementVisitor.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/CheckIrElementVisitor.kt
@@ -26,8 +26,6 @@ import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.ir.types.*
-import org.jetbrains.kotlin.ir.util.getInlineClassUnderlyingType
-import org.jetbrains.kotlin.ir.util.getInlinedClass
 import org.jetbrains.kotlin.ir.util.isAnnotationClass
 import org.jetbrains.kotlin.ir.util.render
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
@@ -109,11 +107,16 @@ class CheckIrElementVisitor(
         }
 
         var type = expression.type
+        /*
+        TODO: This check used to have JS inline class helpers. Rewrite it in a common way.
         while (true) {
             val inlinedClass = type.getInlinedClass() ?: break
+            if (getInlineClassUnderlyingType(inlinedClass) == type)
+                break
             type = getInlineClassUnderlyingType(inlinedClass)
         }
         expression.ensureTypesEqual(type, naturalType)
+        */
     }
 
     override fun visitStringConcatenation(expression: IrStringConcatenation) {
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsIrBackendContext.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsIrBackendContext.kt
index 6dbe2803a91..1c42307b0ab 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsIrBackendContext.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsIrBackendContext.kt
@@ -18,6 +18,7 @@ import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
 import org.jetbrains.kotlin.ir.backend.js.lower.JsInnerClassesSupport
 import org.jetbrains.kotlin.ir.backend.js.utils.OperatorNames
 import org.jetbrains.kotlin.ir.builders.declarations.addFunction
+import org.jetbrains.kotlin.ir.backend.js.utils.getInlinedClass
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrExternalPackageFragmentImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrFileImpl
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/AutoboxingTransformer.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/AutoboxingTransformer.kt
index 35836a80d4f..8bd87b0347f 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/AutoboxingTransformer.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/AutoboxingTransformer.kt
@@ -9,6 +9,8 @@ import org.jetbrains.kotlin.backend.common.BodyLoweringPass
 import org.jetbrains.kotlin.backend.common.lower.AbstractValueUsageTransformer
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
+import org.jetbrains.kotlin.ir.backend.js.utils.getInlinedClass
+import org.jetbrains.kotlin.ir.backend.js.utils.isInlined
 import org.jetbrains.kotlin.ir.backend.js.utils.realOverrideTarget
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.*
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ES6ConstructorLowering.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ES6ConstructorLowering.kt
index cdcfa1704a2..699a22179e0 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ES6ConstructorLowering.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ES6ConstructorLowering.kt
@@ -317,7 +317,7 @@ class ES6ConstructorLowering(val context: JsIrBackendContext) : BodyLoweringPass
             if (superCall.symbol.owner.valueParameters[i].origin === ES6_INIT_BOX_PARAMETER) {
                 result += JsIrBuilder.buildGetValue(boxSymbol!!)
             } else {
-                if (arg.type.getInlinedClass() != null) {
+                if (context.inlineClassesUtils.getInlinedClass(arg.type) != null) {
                     val any = context.irBuiltIns.anyNType
                     result += JsIrBuilder.buildTypeOperator(any, IrTypeOperator.REINTERPRET_CAST, arg, any)
                 } else {
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/TypeOperatorLowering.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/TypeOperatorLowering.kt
index 27dc438b52d..01e2a169d57 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/TypeOperatorLowering.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/TypeOperatorLowering.kt
@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrArithBuilder
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
+import org.jetbrains.kotlin.ir.backend.js.utils.getInlinedClass
 import org.jetbrains.kotlin.ir.backend.js.utils.isPure
 import org.jetbrains.kotlin.ir.declarations.IrClass
 import org.jetbrains.kotlin.ir.declarations.IrDeclaration
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/VarargLowering.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/VarargLowering.kt
index 7afd3f27f1e..860b9119126 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/VarargLowering.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/VarargLowering.kt
@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.backend.common.BodyLoweringPass
 import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
+import org.jetbrains.kotlin.ir.backend.js.utils.getInlinedClass
 import org.jetbrains.kotlin.ir.declarations.IrDeclaration
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/StateMachineBuilder.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/StateMachineBuilder.kt
index 59a7b6d25bd..3016960ae2f 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/StateMachineBuilder.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/StateMachineBuilder.kt
@@ -16,6 +16,7 @@ import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
 import org.jetbrains.kotlin.ir.backend.js.utils.isPure
+import org.jetbrains.kotlin.ir.backend.js.utils.getInlinedClass
 import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.declarations.IrVariable
 import org.jetbrains.kotlin.ir.expressions.*
@@ -29,7 +30,6 @@ import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.isNothing
 import org.jetbrains.kotlin.ir.types.isUnit
 import org.jetbrains.kotlin.ir.util.deepCopyWithSymbols
-import org.jetbrains.kotlin.ir.util.getInlinedClass
 import org.jetbrains.kotlin.ir.visitors.*
 
 class SuspendState(type: IrType) {
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/SuspendLoweringUtils.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/SuspendLoweringUtils.kt
index 5d9806d720e..13706f08fd9 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/SuspendLoweringUtils.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/coroutines/SuspendLoweringUtils.kt
@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.backend.common.ir.isSuspend
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
+import org.jetbrains.kotlin.ir.backend.js.utils.getInlinedClass
 import org.jetbrains.kotlin.ir.declarations.IrVariable
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrGetFieldImpl
@@ -18,7 +19,6 @@ import org.jetbrains.kotlin.ir.symbols.IrReturnableBlockSymbol
 import org.jetbrains.kotlin.ir.symbols.IrValueSymbol
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.isUnit
-import org.jetbrains.kotlin.ir.util.getInlinedClass
 import org.jetbrains.kotlin.ir.visitors.*
 
 object COROUTINE_ROOT_LOOP : IrStatementOriginImpl("COROUTINE_ROOT_LOOP")
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/JsIntrinsicTransformers.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/JsIntrinsicTransformers.kt
index cb1bef1dee7..6015dcf7814 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/JsIntrinsicTransformers.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/JsIntrinsicTransformers.kt
@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.ir.backend.js.transformers.irToJs
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.utils.JsGenerationContext
 import org.jetbrains.kotlin.ir.backend.js.utils.Namer
+import org.jetbrains.kotlin.ir.backend.js.utils.getInlinedClass
 import org.jetbrains.kotlin.ir.declarations.IrClass
 import org.jetbrains.kotlin.ir.declarations.IrConstructor
 import org.jetbrains.kotlin.ir.declarations.IrDeclarationWithName
@@ -19,7 +20,6 @@ import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.ir.types.classifierOrFail
 import org.jetbrains.kotlin.ir.util.getInlineClassBackingField
-import org.jetbrains.kotlin.ir.util.getInlinedClass
 import org.jetbrains.kotlin.ir.util.isEffectivelyExternal
 import org.jetbrains.kotlin.js.backend.ast.*
 
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/IrTypeUtils.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/IrTypeUtils.kt
index f980575bfb4..506e799778c 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/IrTypeUtils.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/IrTypeUtils.kt
@@ -5,11 +5,14 @@
 
 package org.jetbrains.kotlin.ir.backend.js.utils
 
+import org.jetbrains.kotlin.ir.declarations.IrClass
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrClassifierSymbol
+import org.jetbrains.kotlin.ir.symbols.IrScriptSymbol
 import org.jetbrains.kotlin.ir.symbols.IrTypeParameterSymbol
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.fqNameWhenAvailable
+import org.jetbrains.kotlin.ir.util.getInlineClassUnderlyingType
 import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.utils.addToStdlib.ifNotEmpty
 
@@ -38,3 +41,42 @@ private fun IrClassifierSymbol.asString() = when (this) {
     is IrClassSymbol -> this.owner.fqNameWhenAvailable!!.asString()
     else -> error("Unexpected kind of IrClassifierSymbol: " + javaClass.typeName)
 }
+
+/**
+ * Returns inline class for given class or null of type is not inlined
+ */
+fun IrType.getInlinedClass(): IrClass? {
+    if (this is IrSimpleType) {
+        val erased = erase(this) ?: return null
+        if (erased.isInline) {
+            if (this.isMarkedNullable()) {
+                var fieldType: IrType
+                var fieldInlinedClass = erased
+                while (true) {
+                    fieldType = getInlineClassUnderlyingType(fieldInlinedClass)
+                    if (fieldType.isMarkedNullable()) {
+                        return null
+                    }
+
+                    fieldInlinedClass = fieldType.getInlinedClass() ?: break
+                }
+            }
+
+            return erased
+        }
+    }
+    return null
+}
+
+fun IrType.isInlined(): Boolean = this.getInlinedClass() != null
+
+tailrec fun erase(type: IrType): IrClass? {
+    val classifier = type.classifierOrFail
+
+    return when (classifier) {
+        is IrClassSymbol -> classifier.owner
+        is IrTypeParameterSymbol -> erase(classifier.owner.superTypes.first())
+        is IrScriptSymbol -> null
+        else -> error(classifier)
+    }
+}