diff --git a/modules/system/system.module b/modules/system/system.module
index c3b4a1e3915e71e6f4116b5e799d787ea9234c6f..8fc0ffa4309ad01d428f7dfebcf0eeda22099071 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -3018,6 +3018,7 @@ function system_cron() {
     ->fields(array(
       'expire' => 0,
     ))
+    ->condition('expire', 0, '<>')
     ->condition('expire', REQUEST_TIME, '<')
     ->execute();
 }