How to grant execute on FND_MESSAGE?

Normal grant to the package completes successfully, but the usr still cannot execute it

As sys:

SQL> grant execute on apps.fnd_message to xxuser;

Grant succeeded.

Connect as xxuser:

select * from user_tab_privs -> shows that the user does not have the privilege and

SQL> select apps.fnd_message.get from dual;

       *

ERROR at line 1:

ORA-01031: insufficient privileges