diff --git a/backend/core/routes.py b/backend/core/routes.py
index 60a943b9..8ec7cd34 100644
--- a/backend/core/routes.py
+++ b/backend/core/routes.py
@@ -372,6 +372,8 @@ def confirm_reservation():
     event = resa.event
     if not event.is_reservation_possible_for(resa.nb_participants):
         raise EventIsFull
+    elif not event.capacity:
+        resa.liste_attente = False
     elif event.sum_participants + resa.nb_participants <= event.capacity:
         resa.liste_attente = False
     else: