diff --git a/menu_block.module b/menu_block.module
index ae1c4c4..4125328 100644
--- a/menu_block.module
+++ b/menu_block.module
@@ -4,8 +4,11 @@
  * Provides configurable blocks of menu items.
  */
 
-// A core bug in Drupal 7.0 requires this fix.
-module_load_include('inc', 'menu_block', 'custom_menu_active_trail');
+// A core bug fixed in Drupal 7.12.
+// @see http://drupal.org/node/942782
+if (!defined('MENU_PREFERRED_LINK')) {
+  module_load_include('inc', 'menu_block', 'custom_menu_active_trail');
+}
 
 /**
  * Denotes that the tree should use the menu picked by the curent page.