Can't set password when using has_secure_password on parent

[dkolath]

If I use Rails 3.1 has_secure_password in the parent, creating a new record fails with ActiveRecord::UnknownAttributeError: unknown attribute: password

sub_user = SubUser.create!(:password => "foo", :email => "foo")

I am currently able to work-around this by defining has_secure_password on each inheriting class, but of course not the ideal solution.