diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index 946d926b4b2..0d8ed02cac5 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -339,7 +339,7 @@ function page_get_cache() {
  *   The name of the bootstrap hook we wish to invoke.
  */
 function bootstrap_invoke_all($hook) {
-  foreach (module_list(FALSE, TRUE) as $module) {
+  foreach (module_list(TRUE, TRUE) as $module) {
     drupal_load('module', $module);
     module_invoke($module, $hook);
  }
diff --git a/includes/module.inc b/includes/module.inc
index b3c07625096..03bc4f8a1cc 100644
--- a/includes/module.inc
+++ b/includes/module.inc
@@ -45,12 +45,8 @@ function module_list($refresh = FALSE, $bootstrap = TRUE, $sort = FALSE) {
   static $list, $sorted_list;
 
   if ($refresh) {
+    unset($sorted_list);
     $list = array();
-    $sorted_list = NULL;
-  }
-
-  if (!$list) {
-    $list = array('filter' => 'filter', 'node' => 'node', 'system' => 'system', 'user' => 'user', 'watchdog' => 'watchdog');
     if ($bootstrap) {
       $result = db_query("SELECT name, filename, throttle, bootstrap FROM {system} WHERE type = 'module' AND status = 1 AND bootstrap = 1 ORDER BY weight ASC, filename ASC");
     }