diff --git a/django/test/testcases.py b/django/test/testcases.py
index 4de4750aeee..53ea02a4f09 100644
--- a/django/test/testcases.py
+++ b/django/test/testcases.py
@@ -31,7 +31,7 @@ from django.test.client import Client
 from django.test.utils import (get_warnings_state, restore_warnings_state,
     override_settings)
 from django.utils import simplejson, unittest as ut2
-from django.utils.encoding import smart_str
+from django.utils.encoding import smart_str, force_unicode
 from django.views.static import serve
 
 __all__ = ('DocTestRunner', 'OutputChecker', 'TestCase', 'TransactionTestCase',
@@ -335,7 +335,7 @@ class SimpleTestCase(ut2.TestCase):
                 optional.clean(input)
             self.assertEqual(context_manager.exception.messages, errors)
         # test required inputs
-        error_required = [u'This field is required.']
+        error_required = [force_unicode(required.error_messages['required'])]
         for e in EMPTY_VALUES:
             with self.assertRaises(ValidationError) as context_manager:
                 required.clean(e)
diff --git a/tests/regressiontests/test_utils/tests.py b/tests/regressiontests/test_utils/tests.py
index c192d51d556..eab6895f0dd 100644
--- a/tests/regressiontests/test_utils/tests.py
+++ b/tests/regressiontests/test_utils/tests.py
@@ -1,6 +1,6 @@
 from __future__ import with_statement, absolute_import
 
-from django.forms import EmailField
+from django.forms import EmailField, IntegerField
 from django.test import SimpleTestCase, TestCase, skipUnlessDBFeature
 from django.utils.unittest import skip
 
@@ -149,6 +149,12 @@ class AssertFieldOutputTests(SimpleTestCase):
         self.assertRaises(AssertionError, self.assertFieldOutput, EmailField, {'a@a.com': 'Wrong output'}, {'aaa': error_invalid})
         self.assertRaises(AssertionError, self.assertFieldOutput, EmailField, {'a@a.com': 'a@a.com'}, {'aaa': [u'Come on, gimme some well formatted data, dude.']})
 
+    def test_custom_required_message(self):
+        class MyCustomField(IntegerField):
+            default_error_messages = {
+                'required': u'This is really required.',
+            }
+        self.assertFieldOutput(MyCustomField, {}, {}, empty_value=None)
 
 __test__ = {"API_TEST": r"""
 # Some checks of the doctest output normalizer.