diff --git a/json-builder.cabal b/json-builder.cabal
--- a/json-builder.cabal
+++ b/json-builder.cabal
@@ -1,5 +1,5 @@
 Name:                json-builder
-Version:             0.2.0
+Version:             0.2.1
 Synopsis:            Data structure agnostic JSON serialization
 License:             BSD3
 License-file:        LICENSE
@@ -44,4 +44,4 @@
 source-repository this
   type:     git
   location: http://github.com/lpsmith/json-builder
-  tag:      v0.2.0
+  tag:      v0.2.1
diff --git a/src/Data/Json/Builder.hs b/src/Data/Json/Builder.hs
--- a/src/Data/Json/Builder.hs
+++ b/src/Data/Json/Builder.hs
@@ -30,6 +30,7 @@
      , Escaped
      , JsArray(toArray)
      , JsObject(toObject)
+     , Monoid(mempty, mappend, mconcat)
      ) where
 
 import           Prelude hiding ((++))
@@ -78,8 +79,14 @@
 class JsObject a where
   toObject :: a -> Object
 
+instance JsObject Object where
+  toObject = id
+
 class JsArray a where
   toArray  :: a -> Array
+
+instance JsArray Array where
+  toArray = id
 
 toBuilder :: Value a => a -> Builder
 toBuilder x = case toJson x of