diff --git a/CRM/Core/Region.php b/CRM/Core/Region.php
index 4f03c9e613023ca2fe1ae7f4ca4fafb879d90ee8..bc125a42817a20171cafdd14e14ca75970fd1a82 100644
--- a/CRM/Core/Region.php
+++ b/CRM/Core/Region.php
@@ -166,7 +166,7 @@ class CRM_Core_Region {
           $smarty->assign('snippet', $tmp);
           break;
         case 'callback':
-          $args = is_array($snippet['arguments']) ? $snippet['arguments'] : array(&$snippet, &$html);
+          $args = isset($snippet['arguments']) ? $snippet['arguments'] : array(&$snippet, &$html);
           $html .= call_user_func_array($snippet['callback'], $args);
           break;
         case 'scriptUrl':