diff --git a/libraries/structure.lib.php b/libraries/structure.lib.php
index bc5a13d17a..f797bd313a 100644
--- a/libraries/structure.lib.php
+++ b/libraries/structure.lib.php
@@ -962,18 +962,19 @@ function PMA_sortableTableHeader($title, $sort, $initial_sort_order = 'ASC')
 
     $_url_params = array(
         'db' => $_REQUEST['db'],
+        'pos' => 0, // We set the position back to 0 every time they sort.
+        'sort' => $sort,
+        'sort_order' => $future_sort_order,
     );
-
-    $url = 'db_structure.php' . PMA_URL_getCommon($_url_params);
-    // We set the position back to 0 every time they sort.
-    $url .= "&pos=0&sort=$sort&sort_order=$future_sort_order";
-    if (! empty($_REQUEST['tbl_type'])) {
-        $url .= "&tbl_type=" . $_REQUEST['tbl_type'];
+    if (PMA_isValid($_REQUEST['tbl_type'], array('view', 'table'))) {
+        $_url_params['tbl_type'] = $_REQUEST['tbl_type'];
     }
     if (! empty($_REQUEST['tbl_group'])) {
-        $url .= "&tbl_group=" . $_REQUEST['tbl_group'];
+        $_url_params['tbl_group'] = $_REQUEST['tbl_group'];
     }
 
+    $url = 'db_structure.php' . PMA_URL_getCommon($_url_params);
+
     return PMA_Util::linkOrButton(
         $url, $title . $order_img, $order_link_params
     );