diff --git a/src/pretix/base/services/orders.py b/src/pretix/base/services/orders.py
index 1bf1685ed..ef8fa717a 100644
--- a/src/pretix/base/services/orders.py
+++ b/src/pretix/base/services/orders.py
@@ -106,7 +106,7 @@ def check_positions(event, dt, positions, quotas_locked):
                 err = err or error_messages['unavailable']
                 quota_ok = False
                 break
-        if quota_ok and not event.presale_end or now() < event.presale_end:
+        if quota_ok and (not event.presale_end or now() < event.presale_end):
             cp = cp.clone()
             positions[i] = cp
             cp.expires = now() + timedelta(
diff --git a/src/pretix/presale/views/cart.py b/src/pretix/presale/views/cart.py
index 06a36515d..639d605ca 100644
--- a/src/pretix/presale/views/cart.py
+++ b/src/pretix/presale/views/cart.py
@@ -107,6 +107,7 @@ class CartAdd(EventViewMixin, CartActionMixin, View):
             return redirect(self.get_failure_url())
 
         self.items = self._items_from_post_data()
+        self._expired = self._re_add_expired_positions()
 
         if not self.items:
             return redirect(self.get_failure_url())
@@ -167,8 +168,6 @@ class CartAdd(EventViewMixin, CartActionMixin, View):
         expiry = now() + timedelta(minutes=self.request.event.settings.get('reservation_time', as_type=int))
         self._extend_existing(expiry)
 
-        _expired = self._re_add_expired_positions()
-
         # Fetch items from the database
         items_cache = {
             i.identity: i for i
@@ -253,7 +252,7 @@ class CartAdd(EventViewMixin, CartActionMixin, View):
                 for quota in quotas:
                     quota.release()
 
-        self._delete_expired(_expired)
+        self._delete_expired(self._expired)
 
         if not self.msg_some_unavailable:
             messages.success(self.request, _('The products have been successfully added to your cart.'))