diff --git a/nodeaccess.module b/nodeaccess.module
index ded2502..419f962 100644
--- a/nodeaccess.module
+++ b/nodeaccess.module
@@ -700,7 +700,7 @@ function nodeaccess_grants_form($form, &$form_state, $node) {
   else {
     $form['keys'] = array(
       '#type' => 'textfield',
-      '#default_value' => $form_values['keys'],
+      '#default_value' => isset($form_values['keys'])? $form_values['keys'] : '',
       '#size' => 40,
     );
   }