diff --git a/wp-includes/taxonomy.php b/wp-includes/taxonomy.php
index 57be9adf84..555fdb3110 100644
--- a/wp-includes/taxonomy.php
+++ b/wp-includes/taxonomy.php
@@ -42,6 +42,7 @@ function create_initial_taxonomies() {
 														'query_var' => false,
 														'rewrite' => false,
 														'show_ui' => false,
+														'_builtin' => true,
 													) ) ;
 
 	register_taxonomy( 'link_category', 'link', array(	'hierarchical' => false,