diff --git a/authority/fixtures/tests.json b/authority/fixtures/tests.json
index ff53116..2f4bf49 100644
--- a/authority/fixtures/tests.json
+++ b/authority/fixtures/tests.json
@@ -16,5 +16,29 @@
             "email": "", 
             "date_joined": "2009-11-02 03:06:19"
         }
+    },
+    {
+        "pk": 1,
+        "model": "auth.group",
+        "fields": {
+            "name": "Test Group 1",
+            "permissions": []
+        }
+    },
+    {
+        "pk": 2,
+        "model": "auth.group",
+        "fields": {
+            "name": "Test Group 2",
+            "permissions": []
+        }
+    },
+    {
+        "pk": 3,
+        "model": "auth.group",
+        "fields": {
+            "name": "Test Group 3",
+            "permissions": []
+        }
     }
 ]
diff --git a/authority/permissions.py b/authority/permissions.py
index 55ac8b2..dde6d0b 100644
--- a/authority/permissions.py
+++ b/authority/permissions.py
@@ -334,6 +334,7 @@ class BasePermission(object):
                     try:
                         perm = Permission.objects.get(
                             user=self.user,
+                            group=self.group,
                             codename=codename,
                             approved=True,
                             content_type=content_type,
@@ -342,6 +343,7 @@ class BasePermission(object):
                     except Permission.DoesNotExist:
                         perm = Permission.objects.create(
                             user=self.user,
+                            group=self.group,
                             content_object=content_object,
                             codename=codename,
                             approved=True,
diff --git a/authority/tests.py b/authority/tests.py
index 20d3c39..792ac5e 100644
--- a/authority/tests.py
+++ b/authority/tests.py
@@ -1,9 +1,10 @@
 from django.conf import settings
 from django.contrib.auth.models import Permission as DjangoPermission
 from django.contrib.auth.models import Group
-from django.test import TestCase
 from django.contrib.contenttypes.models import ContentType
+from django.core.exceptions import MultipleObjectsReturned
 from django.db.models import Q
+from django.test import TestCase
 
 import authority
 from authority import permissions
@@ -94,6 +95,9 @@ class AssignBehaviourTest(TestCase):
 
     def setUp(self):
         self.user = User.objects.get(QUERY)
+        self.group1 = Group.objects.get(name='Test Group 1')
+        self.group2 = Group.objects.get(name='Test Group 2')
+        self.group3 = Group.objects.get(name='Test Group 2')
         self.check = UserPermission(self.user)
 
     def test_add(self):
@@ -102,6 +106,44 @@ class AssignBehaviourTest(TestCase):
         self.assertTrue(isinstance(result[0], DjangoPermission))
         self.assertTrue(self.check.add_user())
 
+    def test_assign_to_group(self):
+        result = UserPermission(group=self.group1).assign(
+            check='delete_user', content_object=self.user)
+
+        self.assertIsInstance(result, list)
+        self.assertIsInstance(result[0], Permission)
+        self.assertTrue(
+            UserPermission(group=self.group1).delete_user(self.user)
+        )
+
+    def test_assign_to_group_does_not_overwrite_other_group_permission(self):
+        UserPermission(group=self.group1).assign(
+            check='delete_user', content_object=self.user)
+        UserPermission(group=self.group2).assign(
+            check='delete_user', content_object=self.user)
+        self.assertTrue(
+            UserPermission(group=self.group2).delete_user(self.user)
+        )
+        self.assertTrue(
+            UserPermission(group=self.group1).delete_user(self.user)
+        )
+
+    def test_assign_to_group_does_not_fail_when_two_group_perms_exist(self):
+        for group in self.group1, self.group2:
+            perm = Permission(
+                group=group,
+                content_object=self.user,
+                codename='user_permission.delete_user',
+                approved=True
+            )
+            perm.save()
+
+        try:
+            UserPermission(group=self.group3).assign(
+                check='delete_user', content_object=self.user)
+        except MultipleObjectsReturned:
+            self.fail("assign() should not have raised this exception")
+
     def test_delete(self):
         result = self.check.assign(content_object=self.user, check="delete_user",)