diff --git a/authrole/auth/backends.py b/authrole/auth/backends.py
index 2896099..0d9f77b 100644
--- a/authrole/auth/backends.py
+++ b/authrole/auth/backends.py
@@ -1,7 +1,6 @@
 from __future__ import unicode_literals
 
 from django.contrib.auth.backends import ModelBackend
-from django.contrib.auth.models import Permission
 
 
 class BaseAuthRoleBackend(ModelBackend):
@@ -16,14 +15,11 @@ def get_role_permissions(self, user_obj, obj=None):
         Returns a set of permission strings that this user has through his/her
         role.
         """
-        if user_obj.is_anonymous() or obj is not None:
+        if user_obj.is_superuser:
             return set()
         if not hasattr(user_obj, '_role_perm_cache'):
-            if user_obj.is_superuser:
-                perms = Permission.objects.all()
-            else:
-                perms = self.fetch_role_permissions(user_obj)
-            perms = perms.values_list('content_type__app_label', 'codename') \
+            perms = self.fetch_role_permissions(user_obj) \
+                .values_list('content_type__app_label', 'codename') \
                 .order_by()
             user_obj._role_perm_cache = set(['%s.%s' % (ct, name)
                                              for ct, name in perms])
diff --git a/tests/fixtures/role.yaml b/tests/fixtures/role.yaml
index 095df6a..aeda34b 100644
--- a/tests/fixtures/role.yaml
+++ b/tests/fixtures/role.yaml
@@ -84,6 +84,14 @@
     is_active: true
     is_superuser: false
     is_staff: false
+- pk: 3
+  model: 'auth.User'
+  fields:
+    username: 'user3'
+    password: 'pbkdf2_sha256$10000$vkRy7QauoLLj$ry+3xm3YX+YrSXbri8s3EcXDIrx5ceM+xQjtpLdw2oE='
+    is_active: true
+    is_superuser: true
+    is_staff: true
 
 - pk: 1
   model: 'tests.MyUser'
diff --git a/tests/tests.py b/tests/tests.py
index 9697045..744dd8e 100644
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -1,5 +1,5 @@
 import django
-from django.contrib.auth.models import Permission
+from django.contrib.auth.models import Permission, AnonymousUser
 from django.test.testcases import TestCase
 
 from authrole.auth.backends import BaseAuthRoleBackend
@@ -9,26 +9,26 @@ class MyBackend(BaseAuthRoleBackend):
     def fetch_role_permissions(self, user_obj):
         return Permission.objects.filter(group__roles__myusers__user=user_obj)
 
-backend = MyBackend()
 
-
-class BackendTestCase(TestCase):
+class MyBackendTestCase(TestCase):
     fixtures = ['role']
 
-    def test_1(self):
+    backend = MyBackend()
+
+    def test_empty_role(self):
         if django.VERSION[:2] < (1, 11):
-            user = backend.authenticate('user1', 'test')
+            user = self.backend.authenticate('user1', 'test')
         else:
-            user = backend.authenticate(None, 'user1', 'test')
-        permissions = backend.get_all_permissions(user)
+            user = self.backend.authenticate(None, 'user1', 'test')
+        permissions = self.backend.get_all_permissions(user)
         self.assertSetEqual(permissions, set())
 
-    def test_2(self):
+    def test_role(self):
         if django.VERSION[:2] < (1, 11):
-            user = backend.authenticate('user2', 'test')
+            user = self.backend.authenticate('user2', 'test')
         else:
-            user = backend.authenticate(None, 'user2', 'test')
-        permissions = backend.get_all_permissions(user)
+            user = self.backend.authenticate(None, 'user2', 'test')
+        permissions = self.backend.get_all_permissions(user)
         self.assertSetEqual(permissions, {
             'app.can_add_model1',
             'app.can_update_model1',
@@ -37,3 +37,17 @@ def test_2(self):
             'app.can_update_model2',
             'app.can_delete_model2',
         })
+
+    def test_unauthorized(self):
+        user = AnonymousUser()
+        permissions = self.backend.get_all_permissions(user)
+        self.assertSetEqual(permissions, set())
+
+    def test_superuser(self):
+        if django.VERSION[:2] < (1, 11):
+            user = self.backend.authenticate('user3', 'test')
+        else:
+            user = self.backend.authenticate(None, 'user3', 'test')
+        permissions = self.backend.get_all_permissions(user)
+        all_permissions = Permission.objects.all().count()
+        self.assertEqual(len(permissions), all_permissions)