diff --git a/src/pretix/base/modelimport_vouchers.py b/src/pretix/base/modelimport_vouchers.py
index 13a123fe0..81ba9f18d 100644
--- a/src/pretix/base/modelimport_vouchers.py
+++ b/src/pretix/base/modelimport_vouchers.py
@@ -44,6 +44,8 @@ class CodeColumn(ImportColumn):
         super().__init__(*args)
 
     def clean(self, value, previous_values):
+        if not value:
+            raise ValidationError(_('A voucher cannot be created without a code.'))
         if value:
             MinLengthValidator(5)(value)
         if value and (value in self._cached or Voucher.objects.filter(event=self.event, code=value).exists()):