[Dovecot] Listen on multiple ports possible using same protocol?

Is it possible to have multiple Listen directives in a dovecot configuration file for the same protocol? I am running dovecot-1.2.11 and I want to be able to use the "standard port" as well as a test port:

protocol imap { listen = *:143 listen = *:10143 ssl_listen = *:993 ssl_listen = *:10993

for example. Or is this more preferably done by pointing dovecot at different configuration files?