diff --git a/admin/configvars.php b/admin/configvars.php
index 75f569e2884..c9626781023 100644
--- a/admin/configvars.php
+++ b/admin/configvars.php
@@ -381,6 +381,7 @@ class configvarrss extends configvar {
         $config->hiddenuserfields = 'none';
     }
     $configfields = array_flip(explode(',', $config->hiddenuserfields));
+    $fieldoptions = '';
     foreach ($fields as $value) {
         $fieldoptions .= '<option value="'.$value.'"';
         if (isset($configfields[$value])) {