diff --git a/js/src/scrollspy.js b/js/src/scrollspy.js
index 0a4708bf972a5face425fbba1ba199689de42fec..84fa9d6a4f7715ade86fb204ff87579692b22923 100644
--- a/js/src/scrollspy.js
+++ b/js/src/scrollspy.js
@@ -186,7 +186,7 @@ const ScrollSpy = (($) => {
 
     _getScrollTop() {
       return this._scrollElement === window ?
-          this._scrollElement.scrollY : this._scrollElement.scrollTop
+          this._scrollElement.pageYOffset : this._scrollElement.scrollTop
     }
 
     _getScrollHeight() {