Brightness stopped working for Tradfri lights

Hello,

Sinds 0.68 the brightness settings for my Tradfri light scenes have stopped working. I’m getting the following error:

Error executing service <ServiceCall light.turn_on: brightness=180, color_temp=450, transition=2.0, entity_id=['light.spot_links', 'light.spot_midden', 'light.spot_rechts', 'light.tv_lamp_links', 'light.tv_lamp_rechts']>
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/homeassistant/core.py", line 1002, in _event_to_service_call
    await service_handler.func(service_call)
  File "/usr/lib/python3.6/site-packages/homeassistant/components/light/__init__.py", line 360, in async_handle_light_service
    await light.async_turn_on(**params)
  File "/usr/lib/python3.6/site-packages/homeassistant/components/light/tradfri.py", line 293, in async_turn_on
    **params))
TypeError: set_dimmer() got an unexpected keyword argument 'brightness'

This is the scene i’m using:

  - entities: 
      group.woonkamer:
        state: on
        color_temp: 450
        transition: 2
        brightness: 180
    name: Avond

Does anybody have a solution?