diff --git a/sticky-header.js b/sticky-header.js
index 4b0b1fd..8d9bab4 100644
--- a/sticky-header.js
+++ b/sticky-header.js
@@ -46,7 +46,7 @@ var jQuery = require('jquery');
                     return false;
                 }
 
-                var scrollbarVerticalPosition = $body.scrollTop();
+                var scrollbarVerticalPosition = $(window).scrollTop();
 
                 var isSticky = false;
                 var isScrollingDown = scrollbarVerticalPosition > scrollbarPreviousVerticalPosition;