diff --git a/cron.php b/cron.php
index cc6f4bffca4..063b1feefd3 100644
--- a/cron.php
+++ b/cron.php
@@ -13,4 +13,5 @@ if (isset($_GET['cron_key']) && variable_get('cron_key', 'drupal') == $_GET['cro
 }
 else {
   watchdog('cron', 'Cron did not run because an invalid key used.', array(), WATCHDOG_NOTICE);
+  drupal_access_denied();
 }