MQTT Switch Configuration error: Invalid config for [switch.mqtt]: [object_id] is an invalid option for [switch.mqtt]

Configuration
,
1

I have this in my configuration.yml

switch:
  - platform: mqtt
    unique_id: "id_based_on_id2"
    name: "id_based_on_name2"
    object_id: "id_based_on_object2"
    command_topic: "cmnd/rf_bridge/rfraw"
    ...

The “object_id” entry is specified here in the docs: MQTT Switch - Home Assistant

If I set the “object_id” I get this error from home assistant:

Invalid config for [switch.mqtt]: [object_id] is an invalid option for [switch.mqtt]. Check: switch.mqtt->object_id. (See ?, line ?).

Am I doing something wrong?