diff --git a/js/src/dropdown.js b/js/src/dropdown.js
index 8f7b9452aaca..fd16e912676b 100644
--- a/js/src/dropdown.js
+++ b/js/src/dropdown.js
@@ -192,7 +192,7 @@ class Dropdown extends BaseComponent {
     if ('ontouchstart' in document.documentElement &&
       !parent.closest(SELECTOR_NAVBAR_NAV)) {
       [].concat(...document.body.children)
-        .forEach(elem => EventHandler.on(elem, 'mouseover', null, noop))
+        .forEach(elem => EventHandler.on(elem, 'mouseover', noop))
     }
 
     this._element.focus()
@@ -427,7 +427,7 @@ class Dropdown extends BaseComponent {
       // empty mouseover listeners we added for iOS support
       if ('ontouchstart' in document.documentElement) {
         [].concat(...document.body.children)
-          .forEach(elem => EventHandler.off(elem, 'mouseover', null, noop))
+          .forEach(elem => EventHandler.off(elem, 'mouseover', noop))
       }
 
       toggles[i].setAttribute('aria-expanded', 'false')