cupsd.conf IPv6

[e0000195 at student.tuwien.ac.at]

hi to all!
currently i'm writing on my master thesis with the subject "migrating small business networks to ipv6" and of course, i want to migrate cups as well. when looking in the cupsd.conf i saw the line with Listen 127.0.0.1:631 --> how do you write an ipv6 address in here (so that it will not be misinterpreted as port)
AND is there anything else to configure??
as long as i didn't find any clue in ./configure -help  that i should include ipv6 support manually i assumed it is included automatically.
thanks for your help in advance!
sylvia