diff --git a/core/apps/orders/serializers/party.py b/core/apps/orders/serializers/party.py
index ebe59b5..61f3b08 100644
--- a/core/apps/orders/serializers/party.py
+++ b/core/apps/orders/serializers/party.py
@@ -89,8 +89,8 @@ class PartyCreateSerializer(serializers.Serializer):
             PartyAmount.objects.create(
                 total_price=Decimal(total_price),
                 party=party,
-                payment_amount=Decimal(total_price) - validated_data.get("discount", 0),
-                cost_amount=Decimal(total_price) - validated_data.get("discount", 0),
+                payment_amount=Decimal(total_price) - Decimal(validated_data.get("discount", 0)),
+                cost_amount=Decimal(total_price) - Decimal(validated_data.get("discount", 0)),
             )
             return party