diff --git a/lib/omb.php b/lib/omb.php
index df4ffb4b2a..13a2f7adf4 100644
--- a/lib/omb.php
+++ b/lib/omb.php
@@ -20,7 +20,7 @@
 if (!defined('LACONICA')) { exit(1); }
 
 require_once('OAuth.php');
-require_once(INSTALLDIR.'lib/oauthstore.php');
+require_once(INSTALLDIR.'/lib/oauthstore.php');
 
 define('OAUTH_NAMESPACE', 'http://oauth.net/core/1.0/');
 define('OMB_NAMESPACE', 'http://openmicroblogging.org/protocol/0.1');