diff --git a/buildbot/masters/datatracker/buildbot_passwords.py.template b/buildbot/masters/datatracker/buildbot_passwords.py.template
index 2aaea1238..7033b203f 100644
--- a/buildbot/masters/datatracker/buildbot_passwords.py.template
+++ b/buildbot/masters/datatracker/buildbot_passwords.py.template
@@ -1,5 +1,5 @@
 # Copyright The IETF Trust 2015-2020, All Rights Reserved
-# -*- coding: utf-8 -*-
+# -*- python; coding: utf-8 -*-
 
 # Uncomment and set passwords below to match those set for the workers, then
 # save as "buildbot_passwords.py"