--- a/browser/extensions/shield-recipe-client/lib/RecipeRunner.jsm
+++ b/browser/extensions/shield-recipe-client/lib/RecipeRunner.jsm
@@ -52,20 +52,20 @@ this.RecipeRunner = {
       // Run right now in dev mode
       this.run();
     }
 
     if (prefs.getBoolPref(FIRST_RUN_PREF)) {
       // Run once immediately after the UI is available. Do this before adding the
       // timer so we can't end up racing it.
       const observer = {
-        observe: (subject, topic, data) => {
+        observe: async (subject, topic, data) => {
           Services.obs.removeObserver(observer, UI_AVAILABLE_NOTIFICATION);
 
-          this.run();
+          await this.run();
           this.registerTimer();
           prefs.setBoolPref(FIRST_RUN_PREF, false);
 
           Services.obs.notifyObservers(null, SHIELD_INIT_NOTIFICATION);
         },
       };
       Services.obs.addObserver(observer, UI_AVAILABLE_NOTIFICATION);
       CleanupManager.addCleanupHandler(() => Services.obs.removeObserver(observer, UI_AVAILABLE_NOTIFICATION));