diff --git a/common.inc.php b/common.inc.php
index f75bfcc..97dbde7 100644
--- a/common.inc.php
+++ b/common.inc.php
@@ -347,6 +347,7 @@ function send_header($title="")
 {
 	global $HEADER_SENT;
 	global $config;
+	global $prependdir;
 
 	//do this so we can use send_header() a little more loosly and not worry about it being sent more than once.
 	if($HEADER_SENT) return;