diff --git a/idea/src/org/jetbrains/jet/plugin/intentions/SpecifyTypeExplicitlyAction.java b/idea/src/org/jetbrains/jet/plugin/intentions/SpecifyTypeExplicitlyAction.java
index af97e547f26..3f3ca864871 100644
--- a/idea/src/org/jetbrains/jet/plugin/intentions/SpecifyTypeExplicitlyAction.java
+++ b/idea/src/org/jetbrains/jet/plugin/intentions/SpecifyTypeExplicitlyAction.java
@@ -84,7 +84,7 @@ public class SpecifyTypeExplicitlyAction extends PsiElementBaseIntentionAction {
             addTypeAnnotation(project, function, type);
         }
         else {
-            assert false;
+            throw new IllegalStateException("Unexpected parent: " + parent);
         }
     }