assigning two ports to one service in firewalld

Is there a way to assign two ports to the same service in firewalld? For example, I would like for the SMTP service to listen on both port 25 and port 465. My first instinct is to change /usr/lib/firewalld/services/smtp.xml to read as follows :

<?xml version="1.0" encoding="utf-8"?>
<service>
  <short>Mail (SMTP)</short>
  <description>This option allows incoming SMTP mail delivery. If you need to allow remote hosts to connect directly to your machine to deliver mail, enable this option. You $
  <port protocol="tcp" port="465"/>
  <!-- is adding a second port here legal and the best approach? -->
  <port protocol="tcp" port="25"/> 
</service>