diff --git a/wp-admin/includes/nav-menu.php b/wp-admin/includes/nav-menu.php
index f864f607ca..0dbcb0ce9b 100644
--- a/wp-admin/includes/nav-menu.php
+++ b/wp-admin/includes/nav-menu.php
@@ -14,7 +14,7 @@ class Walker_Nav_Menu_Edit extends Walker_Nav_Menu {
 	 *
 	 * @param string $output Passed by reference.
 	 */
-	function start_lvl(&$output) {}
+	function start_lvl( &$output, $depth = 0, $args = array() ) {}
 
 	/**
 	 * @see Walker_Nav_Menu::end_lvl()
@@ -22,8 +22,7 @@ class Walker_Nav_Menu_Edit extends Walker_Nav_Menu {
 	 *
 	 * @param string $output Passed by reference.
 	 */
-	function end_lvl(&$output) {
-	}
+	function end_lvl( &$output, $depth = 0, $args = array() ) {}
 
 	/**
 	 * @see Walker::start_el()
@@ -34,7 +33,7 @@ class Walker_Nav_Menu_Edit extends Walker_Nav_Menu {
 	 * @param int $depth Depth of menu item. Used for padding.
 	 * @param object $args
 	 */
-	function start_el(&$output, $item, $depth, $args) {
+	function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
 		global $_wp_nav_menu_max_depth;
 		$_wp_nav_menu_max_depth = $depth > $_wp_nav_menu_max_depth ? $depth : $_wp_nav_menu_max_depth;
 
@@ -231,12 +230,12 @@ class Walker_Nav_Menu_Checklist extends Walker_Nav_Menu {
 		}
 	}
 
-	function start_lvl( &$output, $depth ) {
+	function start_lvl( &$output, $depth = 0, $args = array() ) {
 		$indent = str_repeat( "\t", $depth );
 		$output .= "\n$indent<ul class='children'>\n";
 	}
 
-	function end_lvl( &$output, $depth ) {
+	function end_lvl( &$output, $depth = 0, $args = array() ) {
 		$indent = str_repeat( "\t", $depth );
 		$output .= "\n$indent</ul>";
 	}
@@ -250,7 +249,7 @@ class Walker_Nav_Menu_Checklist extends Walker_Nav_Menu {
 	 * @param int $depth Depth of menu item. Used for padding.
 	 * @param object $args
 	 */
-	function start_el(&$output, $item, $depth, $args) {
+	function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
 		global $_nav_menu_placeholder;
 
 		$_nav_menu_placeholder = ( 0 > $_nav_menu_placeholder ) ? intval($_nav_menu_placeholder) - 1 : -1;
diff --git a/wp-admin/includes/template.php b/wp-admin/includes/template.php
index 6ec147577c..9b2128e257 100644
--- a/wp-admin/includes/template.php
+++ b/wp-admin/includes/template.php
@@ -34,7 +34,7 @@ class Walker_Category_Checklist extends Walker {
 		$output .= "$indent</ul>\n";
 	}
 
-	function start_el( &$output, $category, $depth, $args, $id = 0 ) {
+	function start_el( &$output, $category, $depth = 0, $args = array(), $id = 0 ) {
 		extract($args);
 		if ( empty($taxonomy) )
 			$taxonomy = 'category';
diff --git a/wp-includes/category-template.php b/wp-includes/category-template.php
index cfc0f2a231..699cf99217 100644
--- a/wp-includes/category-template.php
+++ b/wp-includes/category-template.php
@@ -933,7 +933,7 @@ class Walker_CategoryDropdown extends Walker {
 	 * @param int $depth Depth of category. Used for padding.
 	 * @param array $args Uses 'selected' and 'show_count' keys, if they exist.
 	 */
-	function start_el( &$output, $category, $depth, $args, $id = 0 ) {
+	function start_el( &$output, $category, $depth = 0, $args = array(), $id = 0 ) {
 		$pad = str_repeat('&nbsp;', $depth * 3);
 
 		$cat_name = apply_filters('list_cats', $category->name, $category);
diff --git a/wp-includes/class-wp-walker.php b/wp-includes/class-wp-walker.php
index ec905d0420..655e7f4671 100644
--- a/wp-includes/class-wp-walker.php
+++ b/wp-includes/class-wp-walker.php
@@ -80,7 +80,7 @@ class Walker {
 	 *
 	 * @param string $output Passed by reference. Used to append additional content.
 	 */
-	function start_el( &$output, $object, $depth, $args, $current_object_id = 0 )  {}
+	function start_el( &$output, $object, $depth = 0, $args = array(), $current_object_id = 0 )  {}
 
 	/**
 	 * Ends the element output, if needed.
diff --git a/wp-includes/comment-template.php b/wp-includes/comment-template.php
index 48db1f7ea2..c6881b6797 100644
--- a/wp-includes/comment-template.php
+++ b/wp-includes/comment-template.php
@@ -1325,7 +1325,7 @@ class Walker_Comment extends Walker {
 	 * @param int $depth Depth of comment in reference to parents.
 	 * @param array $args
 	 */
-	function start_el( &$output, $comment, $depth, $args, $id = 0 ) {
+	function start_el( &$output, $comment, $depth = 0, $args = array(), $id = 0 ) {
 		$depth++;
 		$GLOBALS['comment_depth'] = $depth;
 		$GLOBALS['comment'] = $comment;
diff --git a/wp-includes/post-template.php b/wp-includes/post-template.php
index 4bf565d43a..e767ea8d71 100644
--- a/wp-includes/post-template.php
+++ b/wp-includes/post-template.php
@@ -1053,7 +1053,7 @@ class Walker_Page extends Walker {
 	 * @param int $current_page Page ID.
 	 * @param array $args
 	 */
-	function start_el( &$output, $page, $depth, $args, $current_page = 0 ) {
+	function start_el( &$output, $page, $depth = 0, $args = array(), $current_page = 0 ) {
 		if ( $depth )
 			$indent = str_repeat("\t", $depth);
 		else
@@ -1135,7 +1135,7 @@ class Walker_PageDropdown extends Walker {
 	 * @param array $args Uses 'selected' argument for selected page to set selected HTML attribute for option element.
 	 * @param int $id
 	 */
-	function start_el(&$output, $page, $depth, $args, $id = 0) {
+	function start_el( &$output, $page, $depth = 0, $args = array(), $id = 0 ) {
 		$pad = str_repeat('&nbsp;', $depth * 3);
 
 		$output .= "\t<option class=\"level-$depth\" value=\"$page->ID\"";