diff --git a/modules/recurring_events_registration/src/Form/RegistrantForm.php b/modules/recurring_events_registration/src/Form/RegistrantForm.php
index 6320b945cec3f7b6c471a7cbd62fff56fff514ea..c799540146d6ebe2b82dbb4506996f2d430f8828 100644
--- a/modules/recurring_events_registration/src/Form/RegistrantForm.php
+++ b/modules/recurring_events_registration/src/Form/RegistrantForm.php
@@ -411,7 +411,7 @@ class RegistrantForm extends ContentEntityForm {
 
     $form_state->setRedirect('entity.registrant.add_form', ['eventinstance' => $event_instance->id()]);
 
-    if ($registration && $registration_open && ($availability > 0 || $waitlist)) {
+    if ($registration && $registration_open && ($availability > 0 || $availability == -1 || $waitlist)) {
       $add_to_waitlist = (int) $form_state->getValue('add_to_waitlist');
       $this->entity->setEventSeries($event_series);
       $this->entity->setEventInstance($event_instance);