diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,6 +1,29 @@
 # Bunz
 JSON beautifier cli tool written in Haskell
 
+## Usage
+```
+λ   bunz [master] + bunz "{\"foo\":\"bar\"}"
+{
+  "foo": "bar"
+}
+
+λ   bunz [master] + cat test.json | bunz
+{
+  "name": "sendy",
+  "popular": false,
+  "friend": {
+    "name": "\"The rock\n\n\t?",
+    "points": [
+      1,
+      2,
+      34,
+      5
+    ]
+  }
+}
+```
+
 ## Installation
 Bunz requires [Haskell stack tool](https://github.com/commercialhaskell/stack) to install
 
diff --git a/app/Main.hs b/app/Main.hs
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -3,10 +3,12 @@
 module Main where
 
 import qualified Beautifier             as B
+import qualified Data.Text.Lazy         as T
+import qualified Data.Text.Lazy.IO      as TextIO
 import           System.Console.CmdArgs ((&=))
 import qualified System.Console.CmdArgs as CA
-import qualified System.Posix.IO        as IO
-import qualified System.Posix.Terminal  as T
+import           System.Posix.IO        (stdInput)
+import           System.Posix.Terminal  (queryTerminal)
 
 data Args = Args { jsonString :: String }
   deriving (Show, CA.Data, CA.Typeable)
@@ -16,16 +18,16 @@
     &= CA.summary "JSON beautifier tool version 0.0.1"
 
 main :: IO ()
-main = T.queryTerminal IO.stdInput >>= run
+main = queryTerminal stdInput >>= run
 
-printBeautified :: String -> IO ()
-printBeautified = putStrLn . B.beautify
+printBeautified :: T.Text -> IO ()
+printBeautified = TextIO.putStr . B.beautify
 
 runFromStdInput :: IO ()
-runFromStdInput = getContents >>= printBeautified
+runFromStdInput = TextIO.getContents >>= printBeautified
 
 runFromArgs :: Args -> IO ()
-runFromArgs (Args { jsonString = str }) = printBeautified str
+runFromArgs (Args { jsonString = str }) = printBeautified $ T.pack str
 
 run :: Bool -> IO ()
 run False = runFromStdInput
diff --git a/bunz.cabal b/bunz.cabal
--- a/bunz.cabal
+++ b/bunz.cabal
@@ -1,5 +1,5 @@
 name:                bunz
-version:             0.0.2
+version:             0.0.3
 synopsis:            CLI tool to beautify JSON string.
 description:         CLI tool to beautify JSON string.
 homepage:            https://github.com/sendyhalim/bunz
@@ -27,6 +27,7 @@
   ghc-options:         -threaded -rtsopts -with-rtsopts=-N
   build-depends:       base
                      , bunz
+                     , text == 1.2.2.2
                      , unix == 2.7.2.1
                      , cmdargs >= 0.10.18
   default-language:    Haskell2010
diff --git a/src/Beautifier.hs b/src/Beautifier.hs
--- a/src/Beautifier.hs
+++ b/src/Beautifier.hs
@@ -8,15 +8,16 @@
   , splitAtHead
   ) where
 
-import           Data.Monoid ((<>))
-import qualified Data.String as S
-import qualified Data.Text   as T
+import           Data.Int       (Int64)
+import           Data.Monoid    ((<>))
+import qualified Data.String    as S
+import qualified Data.Text.Lazy as T
 
 -- Doctest setup
 -- $setup
 -- >>> :set -XOverloadedStrings
 
-type IndentationLevel = Int
+type IndentationLevel = Int64
 
 indentation :: T.Text
 indentation = "  "
@@ -117,5 +118,5 @@
       <> beautifyText (i - 1) (trimmedTail str)
 
 
-beautify :: String -> String
-beautify = T.unpack . beautifyText 0 . T.pack
+beautify :: T.Text -> T.Text
+beautify = beautifyText 0