Remove title bar from widget

I’m trying to set up a dashboard using AppDaemon and the dark flower skin. All’s well, except that I can’t get the title bar for the Weather widget to go away:

I’ve coded it as follows:

darksky_weather:
  widget_type: weather
  widget_style: "font-size: 100%;"
  units: "°C"
  prefer_icons: 1

And added it as ‘darksky_weather (2x1)’.

I’ve looked around the forums, but I get the impression that with the above declaration, it shouldn’t be there - it’s even gone on the dark_flower’s dev’s screenshot.

Any idea what I’m missing?