diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/ir/IrBuilder.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/ir/IrBuilder.kt
index 9b6613f9aa6..17f1b574ceb 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/ir/IrBuilder.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/ir/IrBuilder.kt
@@ -18,7 +18,6 @@ import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.symbols.impl.*
 import org.jetbrains.kotlin.ir.types.IrType
-import org.jetbrains.kotlin.ir.types.classifierOrFail
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.types.Variance
 
@@ -240,12 +239,11 @@ object JsIrBuilder {
     fun buildWhen(type: IrType, branches: List<IrBranch>, origin: IrStatementOrigin = SYNTHESIZED_STATEMENT) =
         IrWhenImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type, origin, branches)
 
-    // TODO drop type symbol here, it's really not needed
-    fun buildTypeOperator(type: IrType, operator: IrTypeOperator, argument: IrExpression, toType: IrType, symbol: IrClassifierSymbol) =
-        IrTypeOperatorCallImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type, operator, toType, symbol, argument)
+    fun buildTypeOperator(type: IrType, operator: IrTypeOperator, argument: IrExpression, toType: IrType) =
+        IrTypeOperatorCallImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type, operator, toType, argument)
 
     fun buildImplicitCast(value: IrExpression, toType: IrType) =
-        buildTypeOperator(toType, IrTypeOperator.IMPLICIT_CAST, value, toType, toType.classifierOrFail)
+        buildTypeOperator(toType, IrTypeOperator.IMPLICIT_CAST, value, toType)
 
 
     fun buildNull(type: IrType) = IrConstImpl.constNull(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type)
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 4131a386363..a0b53661735 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
@@ -657,8 +657,7 @@ class StateMachineBuilder(
             context.irBuiltIns.booleanType,
             IrTypeOperator.INSTANCEOF,
             value,
-            toType,
-            toType.classifierOrNull!!
+            toType
         )
 
     private fun tempVar(type: IrType, name: String = "tmp") =