diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (c) 2011, 2012 Simon Hengel <sol@typeful.net>
+Copyright (c) 2011-2014 Simon Hengel <sol@typeful.net>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/src/Data/String/Builder.hs b/src/Data/String/Builder.hs
--- a/src/Data/String/Builder.hs
+++ b/src/Data/String/Builder.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE DeriveFunctor, TypeSynonymInstances, FlexibleInstances, TypeFamilies #-}
 -- |
 -- The `build` function can be used to construct multi-line string literals in
 -- a monadic way:
@@ -21,17 +21,29 @@
 , BuilderM
 ) where
 
-import Data.String
+import           Control.Applicative
+import           Control.Monad
+import           Data.Monoid
+import           Data.String
 
 -- | A writer monad for string literals.
 data BuilderM a = BuilderM a ShowS
+  deriving Functor
 
+instance Applicative BuilderM where
+  pure = return
+  (<*>) = ap
+
 instance Monad BuilderM where
   return a            = BuilderM a id
   BuilderM a xs >>= f = case f a of
     BuilderM b ys -> BuilderM b (xs . ys)
 
 type Builder = BuilderM ()
+
+instance Monoid Builder where
+  mempty = return ()
+  a `mappend` b = a >> b
 
 -- | Add a literal string.
 literal :: String -> Builder
diff --git a/stringbuilder.cabal b/stringbuilder.cabal
--- a/stringbuilder.cabal
+++ b/stringbuilder.cabal
@@ -1,11 +1,11 @@
 name:             stringbuilder
-version:          0.4.0
+version:          0.5.0
 synopsis:         A writer monad for multi-line string literals
 description:      <https://github.com/sol/stringbuilder#readme>
 category:         Testing
 license:          MIT
 license-file:     LICENSE
-copyright:        (c) 2011, 2012 Simon Hengel
+copyright:        (c) 2011-2014 Simon Hengel
 author:           Simon Hengel <sol@typeful.net>
 maintainer:       Simon Hengel <sol@typeful.net>
 build-type:       Simple