Sip.conf question

I have two changes that I make to sip.conf manually
allow=gsm
allow=g729
My question is, where can I place these so that everytime I upgrade freepbx they dont get overwritten. I had though about placing them in sip_additional.conf but that didnt seem appropriate either. Any help would be appreciated!

Frank

you can create a file called sip_custom.conf and place the syntax in that file. Freepbx does not modify any files with a _custom.conf naming scheme.

I will try that