Index: wp-admin/includes/post.php
===================================================================
--- wp-admin/includes/post.php	(revision 21027)
+++ wp-admin/includes/post.php	(working copy)
@@ -1164,7 +1164,7 @@
 		$content_width = $old_content_width;
 	}
 
-	return apply_filters( 'admin_post_thumbnail_html', $content );
+	return apply_filters( 'admin_post_thumbnail_html', $content, $post_id );
 }
 
 /**