diff --git a/Presenters/GuestParticipationPresenter.php b/Presenters/GuestParticipationPresenter.php
index 5506f1d1a..7a99e28ce 100644
--- a/Presenters/GuestParticipationPresenter.php
+++ b/Presenters/GuestParticipationPresenter.php
@@ -1,6 +1,7 @@
 <?php
 
 require_once(ROOT_DIR . 'Domain/Access/namespace.php');
+require_once(ROOT_DIR . 'lib/Application/Reservation/Notification/namespace.php');
 
 class GuestParticipationPresenter
 {