diff --git a/beetsplug/web/static/beets.js b/beetsplug/web/static/beets.js
index 4167330ad..46bf71bd3 100644
--- a/beetsplug/web/static/beets.js
+++ b/beetsplug/web/static/beets.js
@@ -279,7 +279,7 @@ var AppView = Backbone.View.extend({
 
     updateMediaSession: function (item) {
       if ("mediaSession" in navigator) {
-        album_id = item.get("album_id");
+        const album_id = item.get("album_id");
         album_art_url = "album/" + album_id + "/art";
         navigator.mediaSession.metadata = new MediaMetadata({
           title: item.get("title"),