Index: wp-includes/l10n.php
===================================================================
--- wp-includes/l10n.php	(revision 12085)
+++ wp-includes/l10n.php	(working copy)
@@ -319,6 +319,8 @@
 function load_textdomain($domain, $mofile) {
 	global $l10n;
 
+	$mofile = apply_filters('load_textdomain_file', $mofile, $domain);
+
 	if ( !is_readable( $mofile ) ) return false;
 
 	$mo = new MO();