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 61f85029d52..f1c49df66ae 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
@@ -32,7 +32,7 @@ object JsIrBuilder {
             UNDEFINED_OFFSET,
             type ?: target.owner.returnType,
             target,
-            target.descriptor.typeParametersCount,
+            target.owner.typeParameters.size,
             SYNTHESIZED_STATEMENT
         ).apply {
             typeArguments?.let {