diff --git a/browser/components/bookmarks/public/nsIBookmarkTransactionManager.idl b/browser/components/bookmarks/public/nsIBookmarkTransactionManager.idl
index 1142a81b9b80..87d69d81b1a4 100644
--- a/browser/components/bookmarks/public/nsIBookmarkTransactionManager.idl
+++ b/browser/components/bookmarks/public/nsIBookmarkTransactionManager.idl
@@ -69,7 +69,7 @@ interface nsIBookmarkTransactionManager : nsISupports
    * 
    */
   void createAndCommitTxn(in unsigned long aType,
-                          in aString aAction,
+                          in AString aAction,
                           in nsIRDFNode aItem,
                           in long aIndex,
                           in nsIRDFResource aParent,