--- firefox-43.0/toolkit/mozapps/extensions/internal/XPIProvider.jsm.orig	2015-12-18 15:26:31.375894541 +0800
+++ firefox-43.0/toolkit/mozapps/extensions/internal/XPIProvider.jsm	2015-12-18 15:26:09.405895175 +0800
@@ -1532,6 +1532,10 @@
     return true;
   }
 
+  // Disable verification for system extensions
+  if (aAddon._installLocation.name == KEY_APP_GLOBAL)
+    return false;
+
   // Hotfixes should always have their signature checked
   let hotfixID = Preferences.get(PREF_EM_HOTFIX_ID, undefined);
   if (hotfixID && aAddon.id == hotfixID)