You're right. The issue you've mentioned can be fixed easily - import Data.Generics instead of Generics and get rid of -package lang (I've copied them from the documentation without checking, seems like it's a bit outdated). The real problem is that you can't use "Get a" in generics! And you have the same problem here, because "Get" constructor isn't exported either! But we can make it work using a continuation trick: {-# OPTIONS_GHC -fglasgow-exts -XGenerics #-} module Test where import Control.Monad import Data.Binary import Data.Generics import Data.Int import System.Random class Binary' a where put' :: a -> Put get' :: (a -> Get StdGen) -> Get StdGen put' {| Unit |} Unit = return () get' {| Unit |} f = f Unit put' {| a :+: b |} (Inl x) = putWord8 0 >> put' x put' {| a :+: b |} (Inr y) = putWord8 1 >> put' y get' {| a :+: b |} f = do w <- getWord8 case w of 0 -> get' $ \x -> f $ Inl x _ -> get' $ \y -> f $ Inr y put' {| a :*: b |} (x :*: y) = put' x >> put' y get' {| a :*: b |} f = get' $ \x -> get' $ \y -> f (x :*: y) instance Binary' Int32 where put' = put get' f = get >>= f instance Binary' StdGen instance Binary StdGen where put = put' get = get' return This time I've checked that it really compiles. Pretty much sure it works.