diff --git a/modules/forum/forum.module b/modules/forum/forum.module
index 99083e895c7094757311a662f1dd9a1497646fab..822f06004125c17f4101919acf67fa6d9b89820b 100644
--- a/modules/forum/forum.module
+++ b/modules/forum/forum.module
@@ -618,7 +618,7 @@ function forum_get_topics($tid, $sortby, $forum_per_page) {
   global $user, $forum_topic_list_header;
 
   $forum_topic_list_header = array(
-    array('data' => ' ', 'field' => NULL),
+    NULL,
     array('data' => t('Topic'), 'field' => 'n.title'),
     array('data' => t('Replies'), 'field' => 'l.comment_count'),
     array('data' => t('Created'), 'field' => 'n.created'),