diff --git a/wp-admin/admin-header.php b/wp-admin/admin-header.php
index 9f6402b66a..41caa26ec7 100644
--- a/wp-admin/admin-header.php
+++ b/wp-admin/admin-header.php
@@ -13,7 +13,7 @@ get_admin_page_title();
 
 ?>
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml" <?php language_attributes(); ?>>
+<html xmlns="http://www.w3.org/1999/xhtml" <?php do_action('admin_xml_ns'); ?> <?php language_attributes(); ?>>
 <head>
 <meta http-equiv="Content-Type" content="<?php bloginfo('html_type'); ?>; charset=<?php echo get_option('blog_charset'); ?>" />
 <title><?php bloginfo('name') ?> &rsaquo; <?php echo wp_specialchars( strip_tags( $title ) ); ?> &#8212; WordPress</title>
