diff --git a/wp-admin/cat-js.php b/wp-admin/cat-js.php
index 4029e03575..156e8f5c47 100644
--- a/wp-admin/cat-js.php
+++ b/wp-admin/cat-js.php
@@ -1,5 +1,6 @@
 <?php
 require_once('admin.php');
+header('Content-type: text/javascript; charset=' . get_settings('blog_charset'), true);
 ?>
 var ajaxCat = new sack();
 var newcat;