diff --git a/tests/fixtures_regress/models.py b/tests/fixtures_regress/models.py
index cd381e92bd..48a462ae6d 100644
--- a/tests/fixtures_regress/models.py
+++ b/tests/fixtures_regress/models.py
@@ -249,7 +249,7 @@ class Thingy(models.Model):
 
 
 class M2MToSelf(models.Model):
-    parent = models.ManyToManyField("self", blank=True, null=True)
+    parent = models.ManyToManyField("self", blank=True)
 
 
 @python_2_unicode_compatible