diff --git a/src/pretix/control/forms/vouchers.py b/src/pretix/control/forms/vouchers.py
index 3a7c9dcf8..d08790523 100644
--- a/src/pretix/control/forms/vouchers.py
+++ b/src/pretix/control/forms/vouchers.py
@@ -140,7 +140,7 @@ class VoucherForm(I18nModelForm):
             data['codes'] = [a.strip() for a in data.get('codes', '').strip().split("\n") if a]
             cnt = len(data['codes']) * data.get('max_usages', 0)
         else:
-            cnt = data['max_usages']
+            cnt = data.get('max_usages', 0)
 
         Voucher.clean_item_properties(
             data, self.instance.event,