diff --git a/modoboa/admin/management/commands/subcommands/_repair.py b/modoboa/admin/management/commands/subcommands/_repair.py
index 029e72ae1..7d8b4ea14 100644
--- a/modoboa/admin/management/commands/subcommands/_repair.py
+++ b/modoboa/admin/management/commands/subcommands/_repair.py
@@ -42,8 +42,9 @@ class Repair(BaseCommand):
         if not quiet:
             print(message)
 
-    def fix_owner(self, model, dry_run=False, **options):
-        for obj in model.objects.all():
+    def fix_owner(self, qs, dry_run=False, **options):
+        model = qs.model
+        for obj in qs:
             kw = dict(
                 cls=model.__name__,
                 obj=obj
@@ -62,12 +63,7 @@ class Repair(BaseCommand):
                     elif isinstance(obj, models.DomainAlias):
                         admin = obj.target.admins.first()
                     else:
-                        if obj.domain:
-                            admin = obj.domain.admins.first()
-                        else:
-                            # Alias is an internal alias for domain alias
-                            # we don't care if it's not owned
-                            continue
+                        admin = obj.domain.admins.first()
                     if not admin:
                         # domain has no admin. use the first superuser found
                         admin = User.objects.filter(is_superuser=True,
@@ -81,11 +77,11 @@ class Repair(BaseCommand):
     @known_problem
     def sometimes_objects_have_no_owner(self, **options):
         owned_models = (
-            User,
-            models.Domain,
-            models.Mailbox,
-            models.Alias,
-            models.DomainAlias
+            User.objects.all(),
+            models.Domain.objects.all(),
+            models.DomainAlias.objects.all(),
+            models.Alias.objects.filter(domain__isnull=False),
+            models.Mailbox.objects.filter(domain__isnull=False),
         )
-        for model in owned_models:
-            self.fix_owner(model, **options)
+        for qs in owned_models:
+            self.fix_owner(qs, **options)
diff --git a/modoboa/admin/tests/test_repair.py b/modoboa/admin/tests/test_repair.py
index c50128556..0674abdfa 100644
--- a/modoboa/admin/tests/test_repair.py
+++ b/modoboa/admin/tests/test_repair.py
@@ -26,7 +26,8 @@ class RepairTestCase(ModoTestCase):
         # assert mbox has no owner
         self.assertIs(get_object_owner(mbox), None)
         # fix it. run in quiet mode because we dont want output in tests
-        management.call_command("modo", "repair", "--quiet")
+        ret = management.call_command("modo", "repair", "--quiet")
+        assert ret is None
         # assert its fixed
         self.assertIsNot(get_object_owner(mbox), None)
         self.assertIsNot(get_object_owner(alias), None)
@@ -38,11 +39,13 @@ class RepairTestCase(ModoTestCase):
         # assert mbox has no owner
         self.assertIs(get_object_owner(mbox), None)
         # show problems. run in quiet mode because we dont want output in tests
-        management.call_command("modo", "repair", "--quiet", "--dry-run")
+        ret = management.call_command("modo", "repair", "--quiet", "--dry-run")
+        assert ret is None
         # assert its not fixed
         self.assertIs(get_object_owner(mbox), None)
 
     def test_management_command_with_nul_domain(self):
         """ Just assume nothing raise when an alias has no domain"""
         models.Alias.objects.create(address='@modoboa.xxx')
-        management.call_command("modo", "repair", "--quiet")
+        ret = management.call_command("modo", "repair", "--quiet")
+        assert ret is None
diff --git a/tox.ini b/tox.ini
index 185d3e9e0..ed4170764 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,11 +5,13 @@ envlist = py27
 changedir=test_project
 commands =
     python ../tests.py
-    coverage run --source ../modoboa manage.py test modoboa.core modoboa.lib modoboa.admin.tests modoboa.limits modoboa.relaydomains
+    coverage run --source modoboa manage.py test modoboa.core modoboa.lib modoboa.admin.tests modoboa.limits modoboa.relaydomains
+    coverage report --show-missing
 deps =
     -r{toxinidir}/test-requirements.txt
     coverage
 setenv =
+    COVERAGE_FILE={envdir}/.coverage
     DB=SQLITE
 
 [testenv:serve]