diff --git a/src/js/lightbox.js b/src/js/lightbox.js
index 8d8ea06c..993ba992 100644
--- a/src/js/lightbox.js
+++ b/src/js/lightbox.js
@@ -379,8 +379,8 @@
     */
     setTimeout(function() {
       self.$overlay
-        .width($(document).width())
-        .height($(document).height());
+        .width($(window).width())
+        .height($(window).height());
 
     }, 0);
   };