diff --git a/system/classes/config.class.php b/system/classes/config.class.php
index 7e0df5113..962973442 100644
--- a/system/classes/config.class.php
+++ b/system/classes/config.class.php
@@ -395,10 +395,10 @@ function restore_param($name, $group, $sg = null, $tab_id = null)
         $escaped_name = DB_escapeString($name);
         $escaped_grp = DB_escapeString($group);
 
-        if (empty($tab_id)) {
+        if (empty($tab_id) && $tab_id !== '0') {
             $tab_id = DB_getItem($_TABLES['conf_values'], 'tab',
                     "name = '$escaped_name' AND group_name = '$escaped_grp'");
-            if (empty($tab_id)) return false;
+            if (empty($tab_id && $tab_id !== '0')) return false;
         }
 
         // check if current user other than Root has access to
@@ -440,10 +440,10 @@ function unset_param($name, $group, $sg = null, $tab_id = '')
         $escaped_name = DB_escapeString($name);
         $escaped_grp = DB_escapeString($group);
 
-        if (empty($tab_id)) {
+        if (empty($tab_id) && $tab_id !== '0') {
             $tab_id = DB_getItem($_TABLES['conf_values'], 'tab',
                     "name = '$escaped_name' AND group_name = '$escaped_grp'");
-            if (empty($tab_id)) return false;
+            if (empty($tab_id && $tab_id !== '0')) return false;
         }
 
         // check if current user other than Root has access to