Can't find linux-headers for kernel 4.4.20-v7

I did a rpi-update and now uname -r returns 4.4.20-v7+. But now I can’t find the linux-headers package for this kernel. apt-get install linux-headers-$(uname -r) finds nothing…

Where can I find this package? In need of it to install a wifi driver (TL-WN725N). I’m trying to follow the instructions found here.


I posted this in the wrong section. Fixed now.

Can anyone help me please? Thanks!