"new" nhibernate with dot net 3.5


i need to enhance a older software that uses dot net 3.5 with a ORM layer, since the EF 1 got a vote of no confidence back in 2009 im thinking about using nhibernate.

according to this: https://www.nuget.org/packages/NHibernate/ it only needs:

Iesi.Collections (>= 4.0.0 & < 5.0.0)

but is it a good idea to add a almost current nhibernate to such a old dot net version?

oh, sorry. some old nhibernate forum redirected me here. thanks.