diff --git a/dom/src/base/nsGlobalWindow.cpp b/dom/src/base/nsGlobalWindow.cpp
index 369fdc4928f1..062060b8f0b9 100644
--- a/dom/src/base/nsGlobalWindow.cpp
+++ b/dom/src/base/nsGlobalWindow.cpp
@@ -253,7 +253,11 @@ NS_IMETHODIMP GlobalWindowImpl::SetNewDocument(nsIDOMDocument *aDocument)
       mDocument = nsnull; // Forces Release
    
    if(mContext) 
-      mContext->GC();
+   {
+      // Add an extra ref in case we release mContext during GC.
+      nsCOMPtr<nsIScriptContext> kungFuDeathGrip = mContext;
+      kungFuDeathGrip->GC();
+   }
 
    mDocument = aDocument;