diff --git a/.gitignore b/.gitignore
index 96d3622..d0596e1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 *.egg-info
 *.sql
 docs/build/*
+.DS_Store
\ No newline at end of file
diff --git a/authority/forms.py b/authority/forms.py
index 57f9177..6d3a8f9 100644
--- a/authority/forms.py
+++ b/authority/forms.py
@@ -1,11 +1,16 @@
 from django import forms
 from django.utils.translation import ugettext_lazy as _
 from django.contrib.contenttypes.models import ContentType
-from django.contrib.auth.models import User, Group
+from django.contrib.auth.models import Group
 from django.utils.safestring import mark_safe
 
 from authority import permissions, get_choices_for
 from authority.models import Permission
+from authority.utils import get_user_class
+
+
+User = get_user_class()
+
 
 class BasePermissionForm(forms.ModelForm):
     codename = forms.CharField(label=_('Permission'))
diff --git a/authority/models.py b/authority/models.py
index 1398971..3091f2f 100644
--- a/authority/models.py
+++ b/authority/models.py
@@ -1,4 +1,5 @@
 from datetime import datetime
+from django.conf import settings
 from django.db import models
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes import generic
@@ -7,6 +8,10 @@ from django.utils.translation import ugettext_lazy as _
 
 from authority.managers import PermissionManager
 
+
+USER_MODEL = getattr(settings, 'AUTH_USER_MODEL', 'auth.User')
+
+
 class Permission(models.Model):
     """
     A granular permission model, per-object permission in other words.
@@ -18,9 +23,9 @@ class Permission(models.Model):
     object_id = models.PositiveIntegerField()
     content_object = generic.GenericForeignKey('content_type', 'object_id')
 
-    user = models.ForeignKey(User, null=True, blank=True, related_name='granted_permissions')
+    user = models.ForeignKey(USER_MODEL, null=True, blank=True, related_name='granted_permissions')
     group = models.ForeignKey(Group, null=True, blank=True)
-    creator = models.ForeignKey(User, null=True, blank=True, related_name='created_permissions')
+    creator = models.ForeignKey(USER_MODEL, null=True, blank=True, related_name='created_permissions')
 
     approved = models.BooleanField(_('approved'), default=False, help_text=_("Designates whether the permission has been approved and treated as active. Unselect this instead of deleting permissions."))
 
diff --git a/authority/templatetags/permissions.py b/authority/templatetags/permissions.py
index ffe37a8..e93d1e0 100644
--- a/authority/templatetags/permissions.py
+++ b/authority/templatetags/permissions.py
@@ -1,16 +1,21 @@
 from django import template
 from django.core.urlresolvers import reverse
 from django.core.exceptions import ImproperlyConfigured
-from django.contrib.auth.models import User, AnonymousUser
+from django.contrib.auth.models import AnonymousUser
 from django.core.urlresolvers import reverse
 
 from authority import get_check
 from authority import permissions
 from authority.models import Permission
 from authority.forms import UserPermissionForm
+from authority.utils import get_user_class
+
 
 register = template.Library()
 
+User = get_user_class()
+
+
 @register.simple_tag
 def url_for_obj(view_name, obj):
     return reverse(view_name, kwargs={
diff --git a/authority/tests.py b/authority/tests.py
index 182a854..bddee05 100644
--- a/authority/tests.py
+++ b/authority/tests.py
@@ -1,6 +1,6 @@
 from django.conf import settings
 from django.contrib.auth.models import Permission as DjangoPermission
-from django.contrib.auth.models import User, Group
+from django.contrib.auth.models import Group
 from django.test import TestCase
 from django.contrib.contenttypes.models import ContentType
 
@@ -8,6 +8,10 @@ import authority
 from authority import permissions
 from authority.models import Permission
 from authority.exceptions import NotAModel, UnsavedModelInstance
+from authority.utils import get_user_class
+
+
+User = get_user_class()
 
 
 class UserPermission(permissions.BasePermission):
diff --git a/authority/utils.py b/authority/utils.py
new file mode 100644
index 0000000..f38f0c5
--- /dev/null
+++ b/authority/utils.py
@@ -0,0 +1,8 @@
+from django.contrib import auth
+
+
+def get_user_class():
+    if hasattr(auth, "get_user_model"):
+        return auth.get_user_model()
+    else:
+        return auth.models.User
\ No newline at end of file