Override Squid newsyslog.conf configuration

[Alwaysink]

Hi,
I'd like to change different parameters into /usr/local/etc/newsyslog.conf.d/squid (remove the compression and allow more files, namely). I modified the file directly but it get overriden with the next update.
How do I make the changes permanent ? Do I have to create /usr/local/etc/newsyslog.conf.d/squid and it will have precedence?

Thanks!