diff --git a/authtools/models.py b/authtools/models.py
index cef5da2..1f667cf 100644
--- a/authtools/models.py
+++ b/authtools/models.py
@@ -26,8 +26,7 @@ def create_superuser(self, **kwargs):
 
 
 class AbstractEmailUser(AbstractBaseUser, PermissionsMixin):
-    email = models.EmailField(_('email address'), max_length=255, unique=True,
-                              db_index=True,)
+    email = models.EmailField(_('email address'), max_length=255, unique=True)
 
     is_staff = models.BooleanField(_('staff status'), default=False,
         help_text=_('Designates whether the user can log into this admin '