diff --git a/src/charm.py b/src/charm.py
index 9de4b63e5..d5953b427 100755
--- a/src/charm.py
+++ b/src/charm.py
@@ -604,7 +604,7 @@ def _on_set_password(self, event: ActionEvent) -> None:
 
         # rotate password to shards
         # TODO in the future support rotating passwords of pbm across shards
-        if username == OperatorUser.get_username() or username == BackupUser.get_username:
+        if username in [OperatorUser.get_username(), BackupUser.get_username()]:
             self.config_server.update_credentials(
                 MongoDBUser.get_password_key_name_for_user(username),
                 new_password,