[Haskell-cafe] How do I lift Control.Monad.Reader.local?

I can write a stack push function in the reader monad like so: import Control.Monad.Reader push :: String -> Reader [String] a -> Reader [String] a push s action = local (s :) action How can I write a push that works inside a monad transformer? push' :: MonadTrans t => String -> t (Reader [String]) a -> t (Reader [String]) a push' s action = ???