diff --git a/haskell/src/Data/MessagePack/Object.hs b/haskell/src/Data/MessagePack/Object.hs
index 19a3aeba..df0e89dd 100644
--- a/haskell/src/Data/MessagePack/Object.hs
+++ b/haskell/src/Data/MessagePack/Object.hs
@@ -1,5 +1,6 @@
-{-# LANGUAGE TypeSynonymInstances #-}
-{-# LANGUAGE FlexibleInstances #-}
+{-# Language TypeSynonymInstances #-}
+{-# Language FlexibleInstances #-}
+{-# Language OverlappingInstances #-}
 
 --------------------------------------------------------------------
 -- |