diff --git a/includes/path.inc b/includes/path.inc
index 46c14c71c40..b41fa7d7407 100644
--- a/includes/path.inc
+++ b/includes/path.inc
@@ -335,7 +335,7 @@ function drupal_path_alias_whitelist_rebuild($source = NULL) {
   // path it corresponds to. This is the portion of the path before the first
   // '/', if present, otherwise the whole path itself.
   $whitelist = array();
-  $result = db_query("SELECT SUBSTRING_INDEX(source, '/', 1) AS path FROM {url_alias} GROUP BY path");
+  $result = db_query("SELECT DISTINCT SUBSTRING_INDEX(source, '/', 1) AS path FROM {url_alias}");
   foreach ($result as $row) {
     $whitelist[$row->path] = TRUE;
   }