diff --git modules/system/system.api.php modules/system/system.api.php
index c68d893..068b0f5 100644
--- modules/system/system.api.php
+++ modules/system/system.api.php
@@ -1002,9 +1002,10 @@ function hook_page_build(&$page) {
  *     item. Note that this function is called even if the access checks fail,
  *     so any custom delivery callback function should take that into account.
  *     See drupal_deliver_html_page() for an example.
- *   - "access callback": A function returning a boolean value that determines
- *     whether the user has access rights to this menu item. Defaults to
- *     user_access() unless a value is inherited from a parent menu item.
+ *   - "access callback": A function returning either a boolean value or a
+ *     number that can be cast to a boolean value that determines whether the
+ *     user has access rights to this menu item. Defaults to user_access()
+ *     unless a value is inherited from a parent menu item.
  *   - "access arguments": An array of arguments to pass to the access callback
  *     function, with path component substitution as described above.
  *   - "theme callback": Optional. A function returning the machine-readable