diff --git a/mozilla/mailnews/compose/src/nsMsgCompose.cpp b/mozilla/mailnews/compose/src/nsMsgCompose.cpp
index a49bad1939e..09d0b3e8620 100644
--- a/mozilla/mailnews/compose/src/nsMsgCompose.cpp
+++ b/mozilla/mailnews/compose/src/nsMsgCompose.cpp
@@ -388,6 +388,8 @@ nsresult nsMsgCompose::ResetUrisForEmbeddedObjects()
   PRUint32 i;
 
   nsCOMPtr<nsIEditorMailSupport> mailEditor (do_QueryInterface(m_editor));
+  if (!mailEditor)
+    return NS_ERROR_FAILURE;
 
   nsresult rv = mailEditor->GetEmbeddedObjects(getter_AddRefs(aNodeList));
   if ((NS_FAILED(rv) || (!aNodeList)))