diff --git a/js/prefs.js b/js/prefs.js
index 184363df..cad8b5f5 100644
--- a/js/prefs.js
+++ b/js/prefs.js
@@ -75,7 +75,7 @@ var prefs = new function Prefs() {
   };
 
   // FF may think localStorage is a cookie or that it's not secure
-  const localStorage = tryCatch(() => localStorage) ? window.localStorage : {};
+  const localStorage = tryCatch(() => window.localStorage) ? window.localStorage : {};
 
   // coalesce multiple pref changes in broadcast
   let broadcastPrefs = {};