diff --git a/modules/system/system.module b/modules/system/system.module
index d0a542e..6bd5472 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -1108,7 +1108,7 @@ function system_library() {
     'title' => 'Drupal progress indicator',
     'version' => VERSION,
     'js' => array(
-      'misc/progress.js' => array('group' => JS_DEFAULT, 'cache' => FALSE),
+      'misc/progress.js' => array('group' => JS_DEFAULT, 'cache' => TRUE),
     ),
   );