-from django.contrib.auth.models import AbstractBaseUser, BaseUserManager, Group
+from django.contrib.auth.models import AbstractBaseUser, BaseUserManager, Group, PermissionsMixin
 from django.core import mail, validators
 from django.conf import settings
 from django.core.urlresolvers import reverse
 
-class User(AbstractBaseUser):
+class User(PermissionsMixin, AbstractBaseUser):
     username = models.CharField(...)
     displayname = models.CharField(max_length=150, blank=True)
     email = models.EmailField()
-    groups = models.ManyToManyField(Group)
     banned = models.BooleanField(default=False)
     active = models.BooleanField(default=True)
     date_joined = models.DateField(auto_now_add=True)