diff --git a/zilencer/management/commands/populate_db.py b/zilencer/management/commands/populate_db.py
index 3b322cbd14..2fea0e1584 100644
--- a/zilencer/management/commands/populate_db.py
+++ b/zilencer/management/commands/populate_db.py
@@ -494,9 +494,8 @@ class Command(BaseCommand):
             shiva = get_user_by_delivery_email("shiva@zulip.com", zulip_realm)
             do_change_user_role(shiva, UserProfile.ROLE_MODERATOR, acting_user=None)
 
-            guest_user = get_user_by_delivery_email("polonius@zulip.com", zulip_realm)
-            guest_user.role = UserProfile.ROLE_GUEST
-            guest_user.save(update_fields=["role"])
+            polonius = get_user_by_delivery_email("polonius@zulip.com", zulip_realm)
+            do_change_user_role(polonius, UserProfile.ROLE_GUEST, acting_user=None)
 
             # These bots are directly referenced from code and thus
             # are needed for the test suite.