diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index a21caa6..7e124f0 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -3410,11 +3410,10 @@ function confirm_form($form, $question, $path, $description = NULL, $yes = NULL,
  * for the user by system_admin_compact_page().
  *
  * If the user does not have the cookie, the default value is given by the
- * system variable 'admin_compact_mode', which itself defaults to FALSE. This
- * does not have a user interface to set it: it is a hidden variable which can
- * be set in the settings.php file.
+ * configuration variable 'system.site.admin_compact_mode',
+ * which itself defaults to FALSE.
  *
- * @return
+ * @return bool
  *   TRUE when in compact mode, FALSE when in expanded mode.
  */
 function system_admin_compact_mode() {