generic type information still contains synonyms

The following program:

module test

import StdEnv, StdGeneric

generic g a :: a -> String
g{|Int|} _ = "Int"
g{|RECORD of grd|} f (RECORD a) = grd.grd_name +++ " " +++ f a +++ " (" +++ toString grd.grd_type +++ ")"
g{|FIELD|} f (FIELD a) = f a

instance toString GenType
where
	toString (GenTypeCons a) = a
	toString (GenTypeVar i) = toString i
	toString (GenTypeApp l r) = "(" +++ toString l +++ " " +++ toString r +++ ")"
	toString (GenTypeArrow l r) = "(" +++ toString l +++ "->" +++ toString r +++ ")"

:: Syn :== Int
:: T = {t :: Syn}

derive g T

Start = g{|*|} {t=42}

Produces:

T Int ((Syn->T))

While I expect it (and want it) to produce:

T Int ((Int->T))