permissions needed to see package body

Hi,

I need to create a role for the developers with select on tables/views, but they also need to be able to see the package bodies.

What permission will give them the ability to see package body? 

Does that require EXECUTE ANY PROCEDURE?  

This, in my opinion, is a little bit excessive for developers.  I want to give them only what they need and not more, to protect them from themselves.

Thanks!