Index: wp-admin/edit-form-advanced.php
===================================================================
--- wp-admin/edit-form-advanced.php	(revision 10994)
+++ wp-admin/edit-form-advanced.php	(working copy)
@@ -384,7 +384,7 @@
  * @param object $post
  */
 function post_trackback_meta_box($post) {
-	$form_trackback = '<input type="text" name="trackback_url" id="trackback_url" tabindex="7" value="'. attribute_escape( str_replace("\n", ' ', $post->to_ping) ) .'" />';
+	$form_trackback = '<input type="text" name="trackback_url" id="trackback_url" class="code" tabindex="7" value="'. attribute_escape( str_replace("\n", ' ', $post->to_ping) ) .'" />';
 	if ('' != $post->pinged) {
 		$pings = '<p>'. __('Already pinged:') . '</p><ul>';
 		$already_pinged = explode("\n", trim($post->pinged));