diff --git a/js/src/scrollspy.js b/js/src/scrollspy.js
index b9186db00d..001f7f56c4 100644
--- a/js/src/scrollspy.js
+++ b/js/src/scrollspy.js
@@ -140,6 +140,7 @@ const ScrollSpy = (($) => {
               targetSelector
             ]
           }
+          return null
         })
         .filter((item)  => item)
         .sort((a, b)    => a[0] - b[0])
diff --git a/js/src/util.js b/js/src/util.js
index 070c5ea757..b779c448f4 100644
--- a/js/src/util.js
+++ b/js/src/util.js
@@ -42,6 +42,7 @@ const Util = (($) => {
         if ($(event.target).is(this)) {
           return event.handleObj.handler.apply(this, arguments)
         }
+        return undefined
       }
     }
   }