diff --git a/wp-includes/nav-menu-template.php b/wp-includes/nav-menu-template.php
index b1b8db1ed5..3778142470 100644
--- a/wp-includes/nav-menu-template.php
+++ b/wp-includes/nav-menu-template.php
@@ -81,8 +81,6 @@ class Walker_Nav_Menu extends Walker {
 	function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
 		$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';
 
-		$class_names = '';
-
 		$classes = empty( $item->classes ) ? array() : (array) $item->classes;
 		$classes[] = 'menu-item-' . $item->ID;