foo.diff

diff --git a/tests/one_to_one/models.py b/tests/one_to_one/models.py
index b54cabb..684e4f8 100644
--- a/tests/one_to_one/models.py
+++ b/tests/one_to_one/models.py
@@ -29,6 +29,8 @@ class Restaurant(models.Model):
     def __str__(self):
         return "%s the restaurant" % self.place.name
 
+class Bar(models.Model):
+    place = models.OneToOneField(Place, null=True)
 
 @python_2_unicode_compatible
 class Waiter(models.Model):
diff --git a/tests/one_to_one/tests.py b/tests/one_to_one/tests.py
index b42666a..ff6b127 100644
--- a/tests/one_to_one/tests.py
+++ b/tests/one_to_one/tests.py
@@ -3,7 +3,7 @@ from __future__ import unicode_literals
 from django.db import transaction, IntegrityError
 from django.test import TestCase
 
-from .models import (Place, Restaurant, Waiter, ManualPrimaryKey, RelatedModel,
+from .models import (Place, Restaurant, Bar, Waiter, ManualPrimaryKey, RelatedModel,
     MultiModel)
 
 
@@ -133,4 +133,9 @@ class OneToOneTests(TestCase):
         # Refs. 10811
         place = Place(name='User', address='London')
         with self.assertRaises(ValueError):
-            r = Restaurant.objects.create(place=place, serves_hot_dogs=True, serves_pizza=False)
+            Restaurant.objects.create(place=place, serves_hot_dogs=True, serves_pizza=False)
+        bar = Bar()
+        with self.assertRaises(ValueError):
+            p = Place(name='User', address='London')
+            p.bar = bar
+            p.save()