diff --git a/htdocs/public/eventorganization/attendee_subscription.php b/htdocs/public/eventorganization/attendee_subscription.php
index e40ad552b5c..3084de3f416 100644
--- a/htdocs/public/eventorganization/attendee_subscription.php
+++ b/htdocs/public/eventorganization/attendee_subscription.php
@@ -66,6 +66,7 @@ require_once DOL_DOCUMENT_ROOT.'/core/lib/company.lib.php';
 require_once DOL_DOCUMENT_ROOT.'/core/class/extrafields.class.php';
 require_once DOL_DOCUMENT_ROOT.'/eventorganization/class/conferenceorbooth.class.php';
 require_once DOL_DOCUMENT_ROOT.'/eventorganization/class/conferenceorboothattendee.class.php';
+require_once DOL_DOCUMENT_ROOT.'/projet/class/project.class.php';
 require_once DOL_DOCUMENT_ROOT.'/core/class/html.formcompany.class.php';
 
 // Init vars