diff --git a/test/ably/rest/restchannels_test.py b/test/ably/rest/restchannels_test.py
index b567781f..fdeeb125 100644
--- a/test/ably/rest/restchannels_test.py
+++ b/test/ably/rest/restchannels_test.py
@@ -87,5 +87,5 @@ async def test_without_permissions(self):
         with pytest.raises(AblyException) as excinfo:
             await ably.channels['test_publish_without_permission'].publish('foo', 'woop')
 
-        assert 'not permitted' in excinfo.value.message
+        assert 40160 == excinfo.value.code
         await ably.close()