diff --git a/test_read_only_default/test_read_only_default.py b/test_read_only_default/test_read_only_default.py
deleted file mode 100644
index df17eef22..000000000
--- a/test_read_only_default/test_read_only_default.py
+++ /dev/null
@@ -1,60 +0,0 @@
-from django.db import models
-from rest_framework import serializers
-from rest_framework.validators import (
-    UniqueTogetherValidator,
-)
-
-from rest_framework import viewsets
-import json
-from rest_framework import mixins
-from rest_framework import generics
-from rest_framework.views import APIView
-from rest_framework.response import Response
-from rest_framework import status
-from django.test import TestCase
-from rest_framework import status
-
-
-class ModelTwo(models.Model):
-    testfieldtwo = models.CharField(max_length=60, primary_key=True)
-
-class ModelOne(models.Model):
-    testfield = models.ForeignKey(ModelTwo, on_delete=models.CASCADE)
-    alias = models.CharField(max_length=60)
-    name = models.CharField(max_length=60)
-
-    class Meta:
-        unique_together = ('testfield', 'name',)
-
-
-class ExampleSerializer(serializers.ModelSerializer):
-    altername = serializers.CharField(source="testfield", default=ModelTwo(testfieldtwo="model 2 default"), read_only=True)
-    
-    class Meta:
-        model = ModelOne
-        fields = ('altername' ,'alias', 'name')
-        validators = [
-            UniqueTogetherValidator(
-                queryset=ModelOne.objects.all(),
-                fields=('testfield', 'name')
-            )
-        ]
-
-class ExampleViewSet(mixins.CreateModelMixin,
-                             mixins.UpdateModelMixin,
-                             viewsets.ReadOnlyModelViewSet):
-
-    queryset = ModelOne.objects.all()
-    serializer_class = ExampleSerializer
-
-
-class ExampleTests(TestCase):
-
-    def url(self):
-        return '/example/'
-    
-    def test_created_successfully(self):
-        name = 'blab blah'
-        alias = 'ab ab'
-        response = self.client.post(self.url, {'name': name, 'alias': alias})
-        self.assertEqual(response.status_code, status.HTTP_201_CREATED, response.data)
diff --git a/test_read_only_default/urls.py b/test_read_only_default/urls.py
deleted file mode 100644
index 771983904..000000000
--- a/test_read_only_default/urls.py
+++ /dev/null
@@ -1,11 +0,0 @@
-from django.conf.urls import include, url
-from rest_framework import routers
-from test_read_only_default import ExampleViewSet
-
-router = routers.DefaultRouter()
-router.register(r'example', ExampleViewSet)
-
-urlpatterns = [
-    url('', include(router.urls)),
-    url('api-auth/', include('rest_framework.urls', namespace='rest_framework'))
-]
\ No newline at end of file
diff --git a/tests/test_validators.py b/tests/test_validators.py
index fe31ba235..6b02d3264 100644
--- a/tests/test_validators.py
+++ b/tests/test_validators.py
@@ -365,6 +365,40 @@ class TestUniquenessTogetherValidation(TestCase):
         validator.filter_queryset(attrs=data, queryset=queryset)
         assert queryset.called_with == {'race_name': 'bar', 'position': 1}
 
+class WritableFieldsWithSourceSerializer(serializers.ModelSerializer):
+    name = serializers.CharField(source='race_name')
+
+    class Meta:
+        model = UniquenessTogetherModel
+        fields = ['name', 'position']
+        validators = [
+            UniqueTogetherValidator(
+                queryset=UniquenessTogetherModel.objects.all(),
+                fields=['name', 'position']
+            )
+        ]
+
+class ReadOnlyFieldsWithSourceSerializer(serializers.ModelSerializer):
+    name = serializers.CharField(source='race_name', read_only=True, default='test')
+
+    class Meta:
+        model = UniquenessTogetherModel
+        fields = ['name', 'position']
+        validators = [
+            UniqueTogetherValidator(
+                queryset=UniquenessTogetherModel.objects.all(),
+                fields=['name', 'position']
+            )
+        ]
+
+class TestFieldsWithFieldSource(TestCase):
+    def test_writeable(self):
+        serializer = WritableFieldsWithSourceSerializer(data={'name': 'formula1', 'position': '1'})
+        serializer.is_valid(raise_exception=True)
+
+    def test_read_only(self):
+        serializer = ReadOnlyFieldsWithSourceSerializer(data={'position': '1'})
+        serializer.is_valid(raise_exception=True)
 
 # Tests for `UniqueForDateValidator`
 # ----------------------------------