diff --git a/src/pretix/presale/views/order.py b/src/pretix/presale/views/order.py
index 6c9d0eb9d..f0719acc3 100644
--- a/src/pretix/presale/views/order.py
+++ b/src/pretix/presale/views/order.py
@@ -124,7 +124,10 @@ class TicketPageMixin:
         can_download = all([r for rr, r in allow_ticket_download.send(self.request.event, order=self.order)])
         if self.request.event.settings.ticket_download_date:
             ctx['ticket_download_date'] = self.order.ticket_download_date
-        ctx['can_download'] = can_download and self.order.ticket_download_available and self.order.positions_with_tickets
+        ctx['can_download'] = (
+            can_download and self.order.ticket_download_available and
+            list(self.order.positions_with_tickets)
+        )
         ctx['download_buttons'] = self.download_buttons
 
         ctx['backend_user'] = (