Index: src/wp-admin/admin-header.php
===================================================================
--- src/wp-admin/admin-header.php	(revision 39562)
+++ src/wp-admin/admin-header.php	(working copy)
@@ -77,6 +77,7 @@
 <script type="text/javascript">
 addLoadEvent = function(func){if(typeof jQuery!="undefined")jQuery(document).ready(func);else if(typeof wpOnload!='function'){wpOnload=func;}else{var oldonload=wpOnload;wpOnload=function(){oldonload();func();}}};
 var ajaxurl = '<?php echo admin_url( 'admin-ajax.php', 'relative' ); ?>',
+    resturl = '<?php echo rest_url( '/' ); ?>',
 	pagenow = '<?php echo $current_screen->id; ?>',
 	typenow = '<?php echo $current_screen->post_type; ?>',
 	adminpage = '<?php echo $admin_body_class; ?>',