Making sure a door is locked when hassio starts

I created a file Automations/startup.yaml that should lock the front door whenever hassio starts. However it’s not doing anything. Am I missing something?

- id: hass_start_lock_front_door
  alias: hass start lock front door
  trigger:
    platform: event
    event_type: homeassistant_start
  action:
    - service: lock.lock
      entity_id: lock.front_door

I believe it should be:

- id: hass_start_lock_front_door
  alias: hass start lock front door
  trigger:
    platform: homeassistant
    event: start
  action:
    - service: lock.lock
      entity_id: lock.front_door

See Home Assistant Trigger.