diff --git a/content/base/src/nsCopySupport.cpp b/content/base/src/nsCopySupport.cpp
index 3bf48e7aa242..8925e1f50463 100644
--- a/content/base/src/nsCopySupport.cpp
+++ b/content/base/src/nsCopySupport.cpp
@@ -92,7 +92,7 @@ nsresult nsCopySupport::HTMLCopy(nsISelection *aSel, nsIDocument *aDoc, PRInt16
   
   nsCOMPtr<nsIDocument> doc = do_QueryInterface(aDoc);
   if (doc) {
-    nsIPresShell* shell = doc->GetShellAt(0);
+    nsCOMPtr<nsIPresShell> shell(dont_AddRef(doc->GetShellAt(0)));
     if (shell) {
       nsCOMPtr<nsIPresContext> context;
       shell->GetPresContext(getter_AddRefs(context) );
diff --git a/layout/base/src/nsCopySupport.cpp b/layout/base/src/nsCopySupport.cpp
index 3bf48e7aa242..8925e1f50463 100644
--- a/layout/base/src/nsCopySupport.cpp
+++ b/layout/base/src/nsCopySupport.cpp
@@ -92,7 +92,7 @@ nsresult nsCopySupport::HTMLCopy(nsISelection *aSel, nsIDocument *aDoc, PRInt16
   
   nsCOMPtr<nsIDocument> doc = do_QueryInterface(aDoc);
   if (doc) {
-    nsIPresShell* shell = doc->GetShellAt(0);
+    nsCOMPtr<nsIPresShell> shell(dont_AddRef(doc->GetShellAt(0)));
     if (shell) {
       nsCOMPtr<nsIPresContext> context;
       shell->GetPresContext(getter_AddRefs(context) );