Rspec and validates_existence_of

Hi List

I am using validates_existence_of in some of my Model classes. For
instance I have the following class:

class User < ActiveRecord::Base
belongs_to :department

 validates_existence_of :department


If I create an instance of User in the console and set the department to
be one that does not exist in the db, then a call to valid? returns

However, if I create a rspec test block, that does something similar,
then valid? returns true. It is almost as if rspec is ignoring the
validates_existence_of. Does naybody have any ideas how to fix this?

Thanks in advance