diff --git a/compiler/frontend/src/org/jetbrains/kotlin/psi/KtElementImpl.java b/compiler/frontend/src/org/jetbrains/kotlin/psi/KtElementImpl.java
index b4dd410f029..2b4a0659315 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/psi/KtElementImpl.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/psi/KtElementImpl.java
@@ -58,7 +58,7 @@ public class KtElementImpl extends ASTWrapperPsiElement implements KtElement {
     @Override
     public KtFile getContainingKtFile() {
         PsiFile file = getContainingFile();
-        assert file instanceof KtFile : "KtElement not inside KtFile: " + file + " " + file.getText();
+        assert file instanceof KtFile : "KtElement not inside KtFile: " + file + (file == null ? "" : " " + file.getText());
         return (KtFile) file;
     }