diff --git a/app/code/core/Mage/Catalog/Block/Navigation.php b/app/code/core/Mage/Catalog/Block/Navigation.php
index db9d15ad36e..cc804875db9 100644
--- a/app/code/core/Mage/Catalog/Block/Navigation.php
+++ b/app/code/core/Mage/Catalog/Block/Navigation.php
@@ -288,11 +288,6 @@ protected function _renderCategoryMenuItemHtml(
         $attributes = [];
         $attributes['class'] = implode(' ', $classes);
 
-        if ($hasActiveChildren && !$noEventAttributes) {
-            $attributes['onmouseover'] = 'toggleMenu(this,1)';
-            $attributes['onmouseout'] = 'toggleMenu(this,0)';
-        }
-
         // assemble list item with attributes
         $htmlLi = '<li';
         foreach ($attributes as $attrName => $attrValue) {