diff --git a/src/pretix/base/models/vouchers.py b/src/pretix/base/models/vouchers.py
index 0c8759b370..ee345237f3 100644
--- a/src/pretix/base/models/vouchers.py
+++ b/src/pretix/base/models/vouchers.py
@@ -234,7 +234,7 @@ class Voucher(LoggedModel):
         certain percentage. If the voucher does not modify the price, the
         original price will be returned.
         """
-        if self.value:
+        if self.value is not None:
             if self.price_mode == 'set':
                 return self.value
             elif self.price_mode == 'subtract':
diff --git a/src/tests/base/test_models.py b/src/tests/base/test_models.py
index 38029fb6d7..0c9d5b5f53 100644
--- a/src/tests/base/test_models.py
+++ b/src/tests/base/test_models.py
@@ -421,6 +421,10 @@ class VoucherTestCase(BaseQuotaTestCase):
         v = Voucher.objects.create(event=self.event, price_mode='set', value=Decimal('10.00'))
         v.calculate_price(Decimal('23.42')) == Decimal('10.00')
 
+    def test_calculate_price_set_zero(self):
+        v = Voucher.objects.create(event=self.event, price_mode='set', value=Decimal('0.00'))
+        v.calculate_price(Decimal('23.42')) == Decimal('0.00')
+
     def test_calculate_price_subtract(self):
         v = Voucher.objects.create(event=self.event, price_mode='subtract', value=Decimal('10.00'))
         v.calculate_price(Decimal('23.42')) == Decimal('13.42')