diff --git a/htdocs/ticket/class/api_tickets.class.php b/htdocs/ticket/class/api_tickets.class.php
index e104d425bf4..f3a9c738aac 100644
--- a/htdocs/ticket/class/api_tickets.class.php
+++ b/htdocs/ticket/class/api_tickets.class.php
@@ -17,7 +17,7 @@
 
  use Luracast\Restler\RestException;
 
-require 'ticket.class.php';
+require_once DOL_DOCUMENT_ROOT.'/ticket/class/ticket.class.php';
 require_once DOL_DOCUMENT_ROOT.'/core/lib/ticket.lib.php';