Exporting own "data" type

I am trying to export a module with own types with the following code:

```
{-# LANGUAGE ForeignFunctionInterface #-}
{-# LANGUAGE TemplateHaskell #-}

module RectangleMover where

import Foreign.C
import FFI.Anything.TypeUncurry.Msgpack

data Point = Point Int Int
movePoint :: Point -> Int -> Int -> Point
movePoint (Point x y) dx dy = Point (x + dx) (y + dy)

data Rectangle = Rectangle { corner :: Point, width :: Int, height :: Int }
move :: Rectangle -> Int -> Int -> Rectangle
move r@(Rectangle {corner=c}) dx dy = r { corner = movePoint c dx dy }

foreign export ccall move_export :: CString -> IO CString
move_export :: CString -> IO CString
move_export = export move
```

But when i try to compile this i get the this error message:

> [1 of 1] Compiling RectangleMover ( test.hs, test.o )
>
> test.hs:19:15:
> No instance for (Data.MessagePack.Object.MessagePack Rectangle)
> arising from a use of ‘export’
> In the expression: export move
> In an equation for ‘move_export’: move_export = export move

What am i missing? Or does this package support exporting own types at all?