commenting on polymorphic aggregates possible?

-- value-independent transition function
CREATE AGGREGATE newcnt (   sfunc = int4inc, basetype = 'any', stype = int4,   initcond = '0'
);

COMMENT ON AGGREGATE newcnt (any) IS 'an any agg comment';
ERROR:  syntax error at or near "any" at character 30
COMMENT ON AGGREGATE newcnt (any) IS NULL;
ERROR:  syntax error at or near "any" at character 30

Is there any way of commenting that aggregate?

Chris