Modifying a foreign key constraint?

What's the best way to modify a foreign key constraint?

I need to change a foreign key from ON DELETE NO ACTION to ON DELETE
CASCADE.  Should I just drop the constraint and re-add it?  For example:

ALTER TABLE foo DROP CONSTRAINT foo_bar_id_fkey;

ALTER TABLE foo ADD FOREIGN KEY (foo_bar_id_fkey) REFERENCES bar(id) ON
DELETE CASCADE;

Is there a more compact way to do this, perhaps with a single ALTER
TABLE command?

Thanks!

        Marc