diff --git a/src/pretix/presale/views/cart.py b/src/pretix/presale/views/cart.py
index 21fbfa3d7..34230e7f1 100644
--- a/src/pretix/presale/views/cart.py
+++ b/src/pretix/presale/views/cart.py
@@ -304,7 +304,7 @@ class RedeemView(EventViewMixin, TemplateView):
 
         self.subevent = None
         if request.event.has_subevents:
-            if 'subevent' in request.GET:
+            if request.GET.get('subevent'):
                 self.subevent = get_object_or_404(SubEvent, event=request.event, pk=request.GET.get('subevent'),
                                                   active=True)