Is there any way to disable the backlight on the Paperwhite 4 (2018 model)?

Hi all,

I've just picked myself up a Paperwhite 4 for the convenience of having a backlight, but I'd like to be able to turn it off entirely both for the sake of being able to as well as not wanting to use the (admittedly small) power it uses.

I know this is possible on at least the Paperwhite 2, but is there any way of doing it on the latest model without using a magnet?

Thanks!