diff --git a/msgpack.cabal b/msgpack.cabal
--- a/msgpack.cabal
+++ b/msgpack.cabal
@@ -1,5 +1,5 @@
 Name:               msgpack
-Version:            0.6.0.0
+Version:            0.6.0.1
 Synopsis:           A Haskell implementation of MessagePack
 Description:
   A Haskell implementation of MessagePack <http://msgpack.org/>
diff --git a/src/Data/MessagePack/Object.hs b/src/Data/MessagePack/Object.hs
--- a/src/Data/MessagePack/Object.hs
+++ b/src/Data/MessagePack/Object.hs
@@ -75,7 +75,7 @@
     , liftM ObjectDouble get
     , liftM ObjectRAW get
     , liftM ObjectArray get
-    , liftM ObjectMap get
+    , liftM (ObjectMap . unAssoc) get
     ]
 
 instance Packable Object where
@@ -96,7 +96,7 @@
       ObjectArray arr ->
         put arr
       ObjectMap m ->
-        put m
+        put $ Assoc m
 
 -- | The class of types serializable to and from MessagePack object
 class (Unpackable a, Packable a) => OBJECT a where