How to build contrib pw-radius?

Hi, I'm trying to build the pw-radius module in the contrib directory but can't seem to find the right library to add to the incantation.

I've tried installing the freeradius-dev package as well as the libradiusclient-ng-dev but still no radlib.h. A google on the error message[1] returns *exactly* two results so I'm kind of at a loss.

Can someone point me in the direction of the correct radius package to install to get this built?

[1] test# gcc -shared -I../../../include -Wall -g -o pw-radius.so radius.c -lradius radius.c:27:20: fatal error: radlib.h: No such file or directory compilation terminated.