Remove Mass Assignment Vulnerability

I have a model A which consists of this line :

attr_accessible :name, :address, :street_id

It shows me that there exists a dangerous attribute (:street_id) for mass assignment. I have used the model A at a place as :

A.new(:name => "Test", :address => "RandomPlace", :street_id => 1)

What should I change so that this issue gets resolved?