1 files changed, 4 insertions, 3 deletions
diff --git a/toolkit/mozapps/extensions/internal/AddonUpdateChecker.jsm b/toolkit/mozapps/extensions/internal/AddonUpdateChecker.jsm
index 7e86fceab..d68a0f175 100644
--- a/toolkit/mozapps/extensions/internal/AddonUpdateChecker.jsm
+++ b/toolkit/mozapps/extensions/internal/AddonUpdateChecker.jsm
@@ -765,8 +765,9 @@ this.AddonUpdateChecker = {
    * @return UpdateParser so that the caller can use UpdateParser.cancel() to shut
    *         down in-progress update requests
    */
-  checkForUpdates: function AUC_checkForUpdates(aId, aUpdateKey, aUrl,
-                                                aObserver) {
-    return new UpdateParser(aId, aUpdateKey, aUrl, aObserver);
+  checkForUpdates: function AUC_checkForUpdates(aId, aUpdateKey, aUrl, aObserver) {
+    // Exclude default theme
+    if (aId != "{972ce4c6-7e08-4474-a285-3208198ce6fd}")
+        return new UpdateParser(aId, aUpdateKey, aUrl, aObserver);
   }
 };