PJSIP: specify external port in transport

Hi all,
As we know, in PJSIP we can specify external IP addresses for signalling and media with the following commands:

external_media_address=<external IP>
external_signaling_address=<external IP>

This presumes that the internal port is mapped to this external IP and port 5060.
However, my NAT maps the internal port 5060 to the external port 5061. And I found out that the syntax like…
… does not work.

Is there any other way to specify the external port? Unfortunately, SIP ALG works incorrectly on the network equipment…
P.S. Asterisk 13.23.1

It’s a separate configuration option:

;external_signaling_port=0      ; External port for SIP signalling (default:
                                ; "0")

Thank you Josh - this worked well

For posterity, this option is documented on the wiki: