diff --git a/website/pizzas/api/serializers.py b/website/pizzas/api/serializers.py
index daaf859f55f840d89391b0a3439d24774dd92fce..2490b6abc9cf697b408285bc414b91a7ee1417cb 100644
--- a/website/pizzas/api/serializers.py
+++ b/website/pizzas/api/serializers.py
@@ -37,7 +37,8 @@ class OrderSerializer(serializers.ModelSerializer):
         read_only_fields = ('pk', 'payment', 'name', 'member')
 
     payment = PaymentTypeField(source='payment.type',
-                               choices=Payment.PAYMENT_TYPE)
+                               choices=Payment.PAYMENT_TYPE,
+                               read_only=True)
 
 
 class AdminOrderSerializer(serializers.ModelSerializer):
@@ -64,5 +65,6 @@ class AdminOrderSerializer(serializers.ModelSerializer):
         ).get('type', instance.payment.type) != instance.payment.type:
             instance.payment.type = validated_data['payment']['type']
             instance.payment.save()
-        del validated_data['payment']
+        if 'payment' in validated_data:
+            del validated_data['payment']
         return super().update(instance, validated_data)
diff --git a/website/pizzas/api/viewsets.py b/website/pizzas/api/viewsets.py
index 9d24b1cf017c13565f862ce1482a405e330bb9ef..fb51793a94fecab957c577da3540822bbd987273 100644
--- a/website/pizzas/api/viewsets.py
+++ b/website/pizzas/api/viewsets.py
@@ -8,6 +8,7 @@ from rest_framework.mixins import ListModelMixin
 from rest_framework.response import Response
 from rest_framework.viewsets import GenericViewSet, ModelViewSet
 
+from payments.models import Payment
 from pizzas.api import serializers
 from pizzas.models import Product, PizzaEvent, Order
 from pizzas.services import can_change_order
@@ -54,7 +55,7 @@ class OrderViewset(ModelViewSet):
                 return Order.objects.none()
 
             return Order.objects.filter(member=self.request.member,
-                                        paid=False,
+                                        payment__type=Payment.NONE,
                                         pizza_event=event)
         return Order.objects.filter(member=self.request.member,
                                     pizza_event=event)