child's passport reissue who is holding visitor permit

[kwanwoo]

Hi,
I'm holding a study permit, and I applied for PGWP a few days ago
and my son's visitor permit expires this November 30th
so I will extend or apply for his visitor permit soon,

by the way, I noticed that my son's passport expiry date is left less than 2 years.
so, if I reissue his passport now, before applying for extending his visitor permit,
is it ok to just apply for extending visitor permit with the new passport number?
or do I have to inform them that his passport number is changed before applying to extend his visitor permit?

thanks.