diff --git a/wp-blog-header.php b/wp-blog-header.php
index ac7c6f3f6..6513ae11b 100644
--- a/wp-blog-header.php
+++ b/wp-blog-header.php
@@ -1,6 +1,6 @@
 <?php
 
-require(dirname(__FILE__).'/' . 'wp-includes/wp-l10n.php');
+require_once(dirname(__FILE__).'/' . 'wp-includes/wp-l10n.php');
 
 if (!file_exists(dirname(__FILE__).'/' . 'wp-config.php'))
     die(__("There doesn't seem to be a <code>wp-config.php</code> file. I need this before we can get started. Need more help? <a href='http://wordpress.org/docs/faq/#wp-config'>We got it</a>. You can <a href='wp-admin/install-config.php'>create a <code>wp-config.php</code> file through a web interface</a>, but this doesn't work for all server setups. The safest way is to manually create the file."));