diff --git a/idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceTypeAlias/extractionModel.kt b/idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceTypeAlias/extractionModel.kt
index 1a07e534bec..e3f973d952f 100644
--- a/idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceTypeAlias/extractionModel.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceTypeAlias/extractionModel.kt
@@ -57,7 +57,7 @@ class IntroduceTypeAliasData(
                                  return
                 typeReference.resolveInfo = TypeReferenceInfo(typeReference, kotlinType)
 
-                typeElement.typeArgumentsAsTypes.forEach { it.accept(this) }
+                typeElement.typeArgumentsAsTypes.forEach { it?.accept(this) }
             }
         }
         (originalTypeElement.parent as? KtTypeReference ?: originalTypeElement).accept(visitor)