diff --git a/helper.php b/helper.php
index 50e7ad3..33b9161 100644
--- a/helper.php
+++ b/helper.php
@@ -42,6 +42,9 @@ function orph_callback_search_wanted(&$data, $base, $file, $type, $lvl, $opts) {
         // get id of this file
         $id = pathID($file);
 
+        // make sure ID is lowercase
+        $id = utf8_strtolower($id);
+
         //check ACL
         if(auth_quickaclcheck($id) < AUTH_READ) {
             return false;