diff --git a/plugins/lazy-yt/assets/javascripts/lazyYT.js b/plugins/lazy-yt/assets/javascripts/lazyYT.js
index 10673ebd13c..f62cb7ad2f2 100644
--- a/plugins/lazy-yt/assets/javascripts/lazyYT.js
+++ b/plugins/lazy-yt/assets/javascripts/lazyYT.js
@@ -98,7 +98,7 @@
     }
 
     $thumb = $el.find('.ytp-thumbnail').css({
-      'background-image': ['url(//img.youtube.com/vi/', id, '/', thumb_img, ')'].join('')
+      'background-image': `url(http://img.youtube.com/vi/${id}/${thumb_img})`
     })
     .addClass('lazyYT-image-loaded')
     .on('click', function (e) {