Is it possible to alter the check clauses in a domain

I have the following domain

CREATE DOMAIN dm_ModeType AS CHAR(1)
CHECK (VALUE IN ('C','O', 'S', 'V'));

and the domain must now be changed to

CREATE DOMAIN dm_ModeType AS CHAR(1)
CHECK (VALUE IN ('C','L','O', 'S', 'V')); ==> added 'L'

regards Cao