diff --git a/tests/test_scheduler.py b/tests/test_scheduler.py
index a1f48fa..70956b4 100644
--- a/tests/test_scheduler.py
+++ b/tests/test_scheduler.py
@@ -2848,7 +2848,7 @@
             for q in p['change_queues']:
                 for head in q['heads']:
                     for change in head:
-                        self.assertEqual(change['id'], 'None')
+                        self.assertEqual(change['id'], None)
                         for job in change['jobs']:
                             status_jobs.add(job['name'])
         self.assertIn('project-bitrot-stable-old', status_jobs)
diff --git a/zuul/model.py b/zuul/model.py
index 3b5a1a5..44780f7 100644
--- a/zuul/model.py
+++ b/zuul/model.py
@@ -770,11 +770,8 @@
 class NullChange(Changeish):
     is_reportable = False
 
-    def __init__(self, project):
-        super(NullChange, self).__init__(project)
-
     def _id(self):
-        return 'None'
+        return None
 
     def equals(self, other):
         return False