--- a/mobile/android/chrome/content/browser.js
+++ b/mobile/android/chrome/content/browser.js
@@ -4187,17 +4187,17 @@ Tab.prototype = {
           if (!isFeed)
             return;
 
           jsonMessage = this.makeFeedMessage(target, type);
         } else if (list.indexOf("[search]") != -1 && aEvent.type == "DOMLinkAdded") {
           this.sendOpenSearchMessage(target);
         } else if (list.indexOf("[manifest]") != -1 &&
                    aEvent.type == "DOMLinkAdded" &&
-                   Services.prefs.getBoolPref("manifest.install.enabled", false)) {
+                   SharedPreferences.forApp().getBoolPref("android.not_a_preference.pwa")){
           jsonMessage = this.makeManifestMessage(target);
         }
         if (!jsonMessage)
          return;
 
         GlobalEventDispatcher.sendRequest(jsonMessage);
         break;
       }