diff --git a/tests/modeltests/validation/models.py b/tests/modeltests/validation/models.py
index 5b90e4b082..8010701823 100644
--- a/tests/modeltests/validation/models.py
+++ b/tests/modeltests/validation/models.py
@@ -102,4 +102,4 @@ try:
         auto2 = models.AutoField(primary_key=True)
 except AssertionError, assertion_error:
     pass # Fail silently
-assert assertion_error.message == u"A model can't have more than one AutoField."
\ No newline at end of file
+assert str(assertion_error) == u"A model can't have more than one AutoField."
\ No newline at end of file
diff --git a/tests/modeltests/validation/test_error_messages.py b/tests/modeltests/validation/test_error_messages.py
index 298f91d8b2..b042c2ee7c 100644
--- a/tests/modeltests/validation/test_error_messages.py
+++ b/tests/modeltests/validation/test_error_messages.py
@@ -17,7 +17,7 @@ class ValidationMessagesTest(TestCase):
         try:
             models.AutoField(primary_key=False)
         except AssertionError, e:
-            self.assertEqual(e.message, u"AutoFields must have primary_key=True.")
+            self.assertEqual(str(e), "AutoFields must have primary_key=True.")
 
     def test_integer_field_raises_error_message(self):
         f = models.IntegerField()