diff --git a/wp-admin/includes/template.php b/wp-admin/includes/template.php
index 734ec77c8..4ecb4a492 100644
--- a/wp-admin/includes/template.php
+++ b/wp-admin/includes/template.php
@@ -1351,7 +1351,6 @@ function iframe_header( $title = '', $limit_styles = false ) {
 	show_admin_bar( false );
 	global $hook_suffix, $current_screen, $current_user, $admin_body_class, $wp_locale;
 	$admin_body_class = preg_replace('/[^a-z0-9_-]+/i', '-', $hook_suffix);
-	$admin_body_class .= ' iframe';
 
 ?><!DOCTYPE html>
 <html xmlns="http://www.w3.org/1999/xhtml" <?php do_action('admin_xml_ns'); ?> <?php language_attributes(); ?>>
@@ -1389,7 +1388,7 @@ do_action("admin_head-$hook_suffix");
 do_action('admin_head');
 ?>
 </head>
-<body<?php if ( isset($GLOBALS['body_id']) ) echo ' id="' . $GLOBALS['body_id'] . '"'; ?>  class="no-js <?php echo $admin_body_class; ?>">
+<body<?php if ( isset($GLOBALS['body_id']) ) echo ' id="' . $GLOBALS['body_id'] . '"'; ?>  class="wp-admin no-js iframe <?php echo apply_filters( 'admin_body_class', '' ) . ' ' . $admin_body_class; ?>">
 <script type="text/javascript">
 //<![CDATA[
 (function(){
diff --git a/wp-admin/nav-menus.php b/wp-admin/nav-menus.php
index 2fcd57815..dd5c7fb1f 100644
--- a/wp-admin/nav-menus.php
+++ b/wp-admin/nav-menus.php
@@ -432,12 +432,12 @@ $_wp_nav_menu_max_depth = 0;
 if ( is_nav_menu( $nav_menu_selected_id ) )
 	$edit_markup = wp_get_nav_menu_to_edit( $nav_menu_selected_id  );
 
-function wp_nav_menu_max_depth() {
+function wp_nav_menu_max_depth($classes) {
 	global $_wp_nav_menu_max_depth;
-	return "menu-max-depth-$_wp_nav_menu_max_depth";
+	return "$classes menu-max-depth-$_wp_nav_menu_max_depth";
 }
 
-add_action('admin_body_class','wp_nav_menu_max_depth');
+add_filter('admin_body_class', 'wp_nav_menu_max_depth');
 
 wp_nav_menu_setup();
 wp_initial_nav_menu_meta_boxes();
diff --git a/wp-admin/widgets.php b/wp-admin/widgets.php
index f606c2754..36e5c3183 100644
--- a/wp-admin/widgets.php
+++ b/wp-admin/widgets.php
@@ -21,8 +21,12 @@ if ( isset($_GET['widgets-access']) ) {
 	set_user_setting( 'widgets_access', $widgets_access );
 }
 
+function wp_widgets_access_body_class($classes) {
+	return "$classes widgets_access ";
+}
+
 if ( 'on' == $widgets_access )
-	add_filter( 'admin_body_class', create_function('', '{return " widgets_access ";}') );
+	add_filter( 'admin_body_class', 'wp_widgets_access_body_class' );
 else
 	wp_enqueue_script('admin-widgets');
 
