diff --git a/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java b/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
index 05b4900ede1e..f6ba9fdb2368 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
@@ -406,7 +406,7 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
   @Override
   public long getModificationStamp() {
     PsiElement context = getContext();
-    PsiFile contextFile = context == null ? null : context.getContainingFile();
+    PsiFile contextFile = context == null || !context.isValid() ? null : context.getContainingFile();
     long contextStamp = contextFile == null ? 0 : contextFile.getModificationStamp();
     return myModificationStamp + contextStamp;
   }