Is there a way to define a synonym that points to another user's procedure of function within a package ?

ex:

USER A: Procedure toto.titi (toto being a package)
GRANT EXECUTE ON TOTO to B_ROLE

USER B (member of B_ROLE): create synonym mytiti for toto.titi
NO errors returned, but when a desc mytiti is issued, it gives me
the package, but not the function.

Thanks.