Can NHibernate use internal types? -

I'm a little bit of a NHibernate noobie, and I was thinking that NHibernate could work with the internal type.

I have a group of internal entities, and I would like to use NHibernate within the project to access my data store . If I am putting mapping files in the same assembly (or is it also necessary?), Would my NHibernate be working with internal institutions? Or do they need to declare them public?