diff --git a/src/pretix/base/services/cart.py b/src/pretix/base/services/cart.py
index 766e5bd021..c945720863 100644
--- a/src/pretix/base/services/cart.py
+++ b/src/pretix/base/services/cart.py
@@ -947,11 +947,11 @@ class CartManager:
 
                 if voucher_available_count < 1:
                     if op.voucher in self._voucher_depend_on_cart:
-                        err = err or error_messages['voucher_redeemed_cart'] % self.event.settings.reservation_time
+                        err = err or _(error_messages['voucher_redeemed_cart']) % self.event.settings.reservation_time
                     else:
                         err = err or error_messages['voucher_redeemed']
                 elif voucher_available_count < requested_count:
-                    err = err or error_messages['voucher_redeemed_partial'] % voucher_available_count
+                    err = err or _(error_messages['voucher_redeemed_partial']) % voucher_available_count
 
                 available_count = min(quota_available_count, voucher_available_count)
 
@@ -1241,6 +1241,7 @@ def add_items_to_cart(self, event: int, items: List[dict], cart_id: str=None, lo
     :raises CartError: On any error that occurred
     """
     with language(locale):
+        print(locale)
         ia = False
         if invoice_address:
             try: