diff --git a/idea/ide-common/src/org/jetbrains/kotlin/util/TypeIndexUtil.kt b/idea/ide-common/src/org/jetbrains/kotlin/util/TypeIndexUtil.kt
index 066c4bdb471..4696ec40bae 100644
--- a/idea/ide-common/src/org/jetbrains/kotlin/util/TypeIndexUtil.kt
+++ b/idea/ide-common/src/org/jetbrains/kotlin/util/TypeIndexUtil.kt
@@ -63,6 +63,7 @@ fun KtTypeReference?.isProbablyNothing(): Boolean {
     return userType.isProbablyNothing()
 }
 
+//TODO: support type aliases
 fun KtUserType?.isProbablyNothing(): Boolean {
     if (this == null) return false
     val referencedName = referencedName