How to add observer to namespace model?

I have a namespace as admin and in this i have class as Admin::Business.
I want to add observer to it. I tried to add a class Admin::BusinessObserver and adding the observer in environment.rb like

config.active_record.observers = [Admin::BusinessObserver]. but it does not work. Can anybody guide me to add observer to namespaced classes.

with Rails 3.1 this worked for me:

   config.active_record.observers = [ :"Admin::BusinessObserver" ]

Came up from looking at how the list is parsed in
gems/1.8/gems/activemodel-3.1.0/lib/active_model/observing.rb line 86


Ankit Varshney wrote in post #907087: