diff --git a/Setup.hs b/Setup.hs
deleted file mode 100644
--- a/Setup.hs
+++ /dev/null
@@ -1,12 +0,0 @@
-module Main where
-
-import Distribution.Simple (defaultMainWithHooks, simpleUserHooks, runTests)
-import System.Process      (system)
-
-main :: IO ()
-main =
-    defaultMainWithHooks $ simpleUserHooks { runTests = runTests' }
-  where
-    runTests' _ _ _ _ = do
-        system "runhaskell -DTEST -i./src src/test.hs"
-        return ()
diff --git a/Setup.lhs b/Setup.lhs
new file mode 100644
--- /dev/null
+++ b/Setup.lhs
@@ -0,0 +1,3 @@
+#!/usr/bin/env runhaskell
+> import Distribution.Simple
+> main = defaultMain
diff --git a/language-dot.cabal b/language-dot.cabal
--- a/language-dot.cabal
+++ b/language-dot.cabal
@@ -1,5 +1,5 @@
 name:         language-dot
-version:      0.1.0
+version:      0.1.1
 category:     Language
 synopsis:     A library for the analysis and creation of Graphviz DOT files
 description:  A library for the analysis and creation of Graphviz DOT files.
@@ -12,15 +12,13 @@
 cabal-version: >= 1.8
 build-type:    Simple
 
-extra-source-files:
-  src/test.hs
-
 flag executable
   description: Build the `ppdot' executable.
   default:     True
 
 library
-  hs-source-dirs: src
+  hs-source-dirs:
+    src
 
   exposed-modules:
     Language.Dot
@@ -35,18 +33,8 @@
     pretty  == 1.*
 
   ghc-options: -Wall
-
-test-suite test
-  type: exitcode-stdio-1.0
-  main-is: test.hs
-  hs-source-dirs: src
-  ghc-options: -Wall
-  cpp-options: -DTEST
-  build-depends:
-    base    == 4.*,
-    mtl     == 1.* || == 2.*,
-    parsec  == 3.*,
-    pretty  == 1.*
+  if impl(ghc >= 6.8)
+    ghc-options: -fwarn-tabs
 
 executable ppdot
   if flag(executable)
@@ -54,16 +42,31 @@
   else
     buildable: False
 
-  main-is: ppdot.hs
-  hs-source-dirs: src
+  hs-source-dirs: ppdot
+
+  main-is: Main.hs
   build-depends:
     base    == 4.*,
     mtl     == 1.* || == 2.*,
-    parsec  == 3.*,
-    pretty  == 1.*
+    language-dot
 
   ghc-options: -Wall
+  if impl(ghc >= 6.8)
+    ghc-options: -fwarn-tabs
 
+test-suite test
+  type: exitcode-stdio-1.0
+  main-is: Main.hs
+  other-modules:
+    Language.Dot.Parser
+    Language.Dot.Syntax
+  hs-source-dirs: test, src
+  ghc-options: -Wall
+  cpp-options: -DTEST
+  build-depends:
+    base    == 4.*,
+    parsec  == 3.*
+
 source-repository head
   type:     git
-  location: git://github.com/bsl/language-dot.git
+  location: https://github.com/bgamari/language-dot
diff --git a/ppdot/Main.hs b/ppdot/Main.hs
new file mode 100644
--- /dev/null
+++ b/ppdot/Main.hs
@@ -0,0 +1,72 @@
+module Main (main) where
+
+import Control.Exception   (IOException, try)
+import Control.Monad.Error (ErrorT(..), MonadError(..))
+import System.Environment  (getArgs, getProgName)
+import System.Exit         (exitFailure, exitSuccess)
+import System.IO           (hPutStrLn, stderr)
+
+import Language.Dot (parseDot, renderDot)
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+
+main :: IO ()
+main =
+    getArgs >>= run
+
+run :: [String] -> IO ()
+run args =
+    case args of
+      [fp] -> renderDotFile fp
+      []   -> displayUsage >> exitSuccess
+      _    -> displayUsage >> exitFailure
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+
+renderDotFile :: FilePath -> IO ()
+renderDotFile fp =
+    runErrorT (renderDotFileET fp) >>= either exitError putStrLn
+
+renderDotFileET :: FilePath -> ErrorT String IO String
+renderDotFileET fp = do
+    contents <- readFile fp `liftCatch` show
+    graph    <- parseDot fp contents `liftEither` show
+    return $ renderDot graph
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+
+displayUsage :: IO ()
+displayUsage = do
+    programName <- getProgName
+    ePutStrLns
+      [ programName ++ ": Pretty-print a Graphviz DOT file."
+      , unwords ["Usage:", programName, "FILE"]
+      ]
+
+exitError :: String -> IO ()
+exitError e = do
+    displayUsage
+    ePutStrLn ""
+    let el = lines e
+    if length el == 1
+      then ePutStrLn  ("ERROR: " ++ e)
+      else ePutStrLns ("ERROR:" : indent el)
+    exitFailure
+  where
+    indent = map ("  "++)
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+
+liftCatch :: IO a -> (IOException -> e) -> ErrorT e IO a
+liftCatch a f = ErrorT $ fmap (either (Left . f) Right) (try a)
+
+liftEither :: (MonadError e m) => Either l r -> (l -> e) -> m r
+liftEither e f = either (throwError . f) return e
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+
+ePutStrLn :: String -> IO ()
+ePutStrLn = hPutStrLn stderr
+
+ePutStrLns :: [String] -> IO ()
+ePutStrLns = mapM_ (hPutStrLn stderr)
diff --git a/src/Language/Dot/Pretty.hs b/src/Language/Dot/Pretty.hs
--- a/src/Language/Dot/Pretty.hs
+++ b/src/Language/Dot/Pretty.hs
@@ -1,9 +1,14 @@
+{-# LANGUAGE CPP #-}
 module Language.Dot.Pretty
   ( prettyPrintDot
   , renderDot
   , PP(..)
   )
   where
+
+#if MIN_VERSION_base(4,11,0)
+import Prelude hiding ((<>))
+#endif
 
 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 
diff --git a/src/ppdot.hs b/src/ppdot.hs
deleted file mode 100644
--- a/src/ppdot.hs
+++ /dev/null
@@ -1,72 +0,0 @@
-module Main (main) where
-
-import Control.Exception   (IOException, try)
-import Control.Monad.Error (ErrorT(..), MonadError(..))
-import System.Environment  (getArgs, getProgName)
-import System.Exit         (exitFailure, exitSuccess)
-import System.IO           (hPutStrLn, stderr)
-
-import Language.Dot (parseDot, renderDot)
-
--- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
-
-main :: IO ()
-main =
-    getArgs >>= run
-
-run :: [String] -> IO ()
-run args =
-    case args of
-      [fp] -> renderDotFile fp
-      []   -> displayUsage >> exitSuccess
-      _    -> displayUsage >> exitFailure
-
--- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
-
-renderDotFile :: FilePath -> IO ()
-renderDotFile fp =
-    runErrorT (renderDotFileET fp) >>= either exitError putStrLn
-
-renderDotFileET :: FilePath -> ErrorT String IO String
-renderDotFileET fp = do
-    contents <- readFile fp `liftCatch` show
-    graph    <- parseDot fp contents `liftEither` show
-    return $ renderDot graph
-
--- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
-
-displayUsage :: IO ()
-displayUsage = do
-    programName <- getProgName
-    ePutStrLns
-      [ programName ++ ": Pretty-print a Graphviz DOT file."
-      , unwords ["Usage:", programName, "FILE"]
-      ]
-
-exitError :: String -> IO ()
-exitError e = do
-    displayUsage
-    ePutStrLn ""
-    let el = lines e
-    if length el == 1
-      then ePutStrLn  ("ERROR: " ++ e)
-      else ePutStrLns ("ERROR:" : indent el)
-    exitFailure
-  where
-    indent = map ("  "++)
-
--- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
-
-liftCatch :: IO a -> (IOException -> e) -> ErrorT e IO a
-liftCatch a f = ErrorT $ fmap (either (Left . f) Right) (try a)
-
-liftEither :: (MonadError e m) => Either l r -> (l -> e) -> m r
-liftEither e f = either (throwError . f) return e
-
--- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
-
-ePutStrLn :: String -> IO ()
-ePutStrLn = hPutStrLn stderr
-
-ePutStrLns :: [String] -> IO ()
-ePutStrLns = mapM_ (hPutStrLn stderr)
diff --git a/src/test.hs b/src/test.hs
deleted file mode 100644
--- a/src/test.hs
+++ /dev/null
@@ -1,120 +0,0 @@
-module Main (main) where
-
-import Control.Monad (unless)
-import Data.Char     (toLower, toUpper)
-
-import Text.Parsec
-import Text.Parsec.String
-
-import Language.Dot.Parser
-import Language.Dot.Syntax
-
--- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
-
-main :: IO ()
-main = do
-    testParser "parsePort"      parsePort      parsePortTests
-    testParser "parseCompass"   parseCompass   parseCompassTests
-    testParser "parseAttribute" parseAttribute parseAttributeTests
-    testParser "parseId"        parseId        parseIdTests
-
--- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
-
-parsePortTests :: [(String, Port)]
-parsePortTests =
-    [ ( ":\"x\""          , PortI (StringId  "x"       ) Nothing          )
-    , ( ":\"\\t\\\"\":nw" , PortI (StringId  "\\t\""   ) (Just CompassNW) )
-    , ( ":-.0004"         , PortI (FloatId   (-0.0004) ) Nothing          )
-    , ( ":-1.23:sE"       , PortI (FloatId   (-1.23)   ) (Just CompassSE) )
-    , ( ":123"            , PortI (IntegerId 123       ) Nothing          )
-    , ( ":123:NE"         , PortI (IntegerId 123       ) (Just CompassNE) )
-    , ( ":__2xYz"         , PortI (NameId    "__2xYz"  ) Nothing          )
-    , ( ":__2xYz:S"       , PortI (NameId    "__2xYz"  ) (Just CompassS)  )
-    , ( ":n"              , PortC CompassN  )
-    , ( ":SE"             , PortC CompassSE )
-    ]
-
-parseCompassTests :: [(String, Compass)]
-parseCompassTests =
-    concat
-      [ [ (t, CompassN)  | t <- allCaps "n"  ]
-      , [ (t, CompassE)  | t <- allCaps "e"  ]
-      , [ (t, CompassS)  | t <- allCaps "s"  ]
-      , [ (t, CompassW)  | t <- allCaps "w"  ]
-      , [ (t, CompassNE) | t <- allCaps "ne" ]
-      , [ (t, CompassNW) | t <- allCaps "nw" ]
-      , [ (t, CompassSE) | t <- allCaps "se" ]
-      , [ (t, CompassSW) | t <- allCaps "sw" ]
-      ]
-
-parseAttributeTests :: [(String, Attribute)]
-parseAttributeTests =
-    [ ( "a"                      , AttributeSetTrue  (NameId "a")                           )
-    , ( "a=b"                    , AttributeSetValue (NameId "a")       (NameId "b")        )
-    , ( "-.003\t=\r\n  _xYz123_" , AttributeSetValue (FloatId (-0.003)) (NameId "_xYz123_") )
-    , ( "\"\\t\\\"\"  =-123"     , AttributeSetValue (StringId "\\t\"") (IntegerId (-123))  )
-    ]
-
-parseIdTests :: [(String, Id)]
-parseIdTests =
-    [ ( "a"             , NameId    "a"         )
-    , ( "A1"            , NameId    "A1"        )
-    , ( "_2X"           , NameId    "_2X"       )
-    , ( "\"\""          , StringId  ""          )
-    , ( "\"\\t\\r\\n\"" , StringId  "\\t\\r\\n" )
-    , ( ".0"            , FloatId   0.0         )
-    , ( ".123"          , FloatId   0.123       )
-    , ( "+.999"         , FloatId   0.999       )
-    , ( "-.001"         , FloatId   (-0.001)    )
-    , ( "+.001"         , FloatId   0.001       )
-    , ( "0.0"           , FloatId   0.0         )
-    , ( "1.2"           , FloatId   1.2         )
-    , ( "123.456"       , FloatId   123.456     )
-    , ( "0"             , IntegerId 0           )
-    , ( "+0"            , IntegerId 0           )
-    , ( "-0"            , IntegerId 0           )
-    , ( "123"           , IntegerId 123         )
-    , ( "-123"          , IntegerId (-123)      )
-    ]
-
--- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
-
-testParser :: (Eq a, Show a) => String -> Parser a -> [(String, a)] -> IO ()
-testParser name parser tests =
-    help tests [] (0 :: Int) (0 :: Int)
-  where
-    help [] es np nf = do
-        putStrLn $ name ++ ": " ++ show np ++ " passed, " ++ show nf ++ " failed"
-        mapM_ (putStrLn . ("  "++)) (reverse es)
-        unless (null es) (putStrLn "")
-    help ((i,o):ts) es np nf =
-        case parse' parser i of
-          Left  _ -> help ts (makeFailureMessage name i o : es) np (succ nf)
-          Right v ->
-            if v /= o
-              then help ts (makeFailureMessage' name i o v : es) np (succ nf)
-              else help ts es (succ np) nf
-
-makeFailureMessage :: (Show a) => String -> String -> a -> String
-makeFailureMessage name i o =
-    "(" ++ name ++ " " ++ show i ++ ")" ++
-    " should have returned " ++ "(" ++ show o ++ ")"
-
-makeFailureMessage' :: (Show a) => String -> String -> a -> a -> String
-makeFailureMessage' name i o v =
-    "(" ++ name ++ " " ++ show i ++ ")" ++
-    " returned "  ++ "(" ++ show v ++ ")" ++
-    ", expected " ++ "(" ++ show o ++ ")"
-
--- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
-
-parse' :: Parser a -> String -> Either ParseError a
-parse' p = parse p ""
-
-allCaps :: String -> [String]
-allCaps []     = [[]]
-allCaps (c:cs) =
-    concatMap (\t -> [l:t, u:t]) (allCaps cs)
-  where
-    l = toLower c
-    u = toUpper c
diff --git a/test/Main.hs b/test/Main.hs
new file mode 100644
--- /dev/null
+++ b/test/Main.hs
@@ -0,0 +1,120 @@
+module Main (main) where
+
+import Control.Monad (unless)
+import Data.Char     (toLower, toUpper)
+
+import Text.Parsec
+import Text.Parsec.String
+
+import Language.Dot.Parser
+import Language.Dot.Syntax
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+
+main :: IO ()
+main = do
+    testParser "parsePort"      parsePort      parsePortTests
+    testParser "parseCompass"   parseCompass   parseCompassTests
+    testParser "parseAttribute" parseAttribute parseAttributeTests
+    testParser "parseId"        parseId        parseIdTests
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+
+parsePortTests :: [(String, Port)]
+parsePortTests =
+    [ ( ":\"x\""          , PortI (StringId  "x"       ) Nothing          )
+    , ( ":\"\\t\\\"\":nw" , PortI (StringId  "\\t\""   ) (Just CompassNW) )
+    , ( ":-.0004"         , PortI (FloatId   (-0.0004) ) Nothing          )
+    , ( ":-1.23:sE"       , PortI (FloatId   (-1.23)   ) (Just CompassSE) )
+    , ( ":123"            , PortI (IntegerId 123       ) Nothing          )
+    , ( ":123:NE"         , PortI (IntegerId 123       ) (Just CompassNE) )
+    , ( ":__2xYz"         , PortI (NameId    "__2xYz"  ) Nothing          )
+    , ( ":__2xYz:S"       , PortI (NameId    "__2xYz"  ) (Just CompassS)  )
+    , ( ":n"              , PortC CompassN  )
+    , ( ":SE"             , PortC CompassSE )
+    ]
+
+parseCompassTests :: [(String, Compass)]
+parseCompassTests =
+    concat
+      [ [ (t, CompassN)  | t <- allCaps "n"  ]
+      , [ (t, CompassE)  | t <- allCaps "e"  ]
+      , [ (t, CompassS)  | t <- allCaps "s"  ]
+      , [ (t, CompassW)  | t <- allCaps "w"  ]
+      , [ (t, CompassNE) | t <- allCaps "ne" ]
+      , [ (t, CompassNW) | t <- allCaps "nw" ]
+      , [ (t, CompassSE) | t <- allCaps "se" ]
+      , [ (t, CompassSW) | t <- allCaps "sw" ]
+      ]
+
+parseAttributeTests :: [(String, Attribute)]
+parseAttributeTests =
+    [ ( "a"                      , AttributeSetTrue  (NameId "a")                           )
+    , ( "a=b"                    , AttributeSetValue (NameId "a")       (NameId "b")        )
+    , ( "-.003\t=\r\n  _xYz123_" , AttributeSetValue (FloatId (-0.003)) (NameId "_xYz123_") )
+    , ( "\"\\t\\\"\"  =-123"     , AttributeSetValue (StringId "\\t\"") (IntegerId (-123))  )
+    ]
+
+parseIdTests :: [(String, Id)]
+parseIdTests =
+    [ ( "a"             , NameId    "a"         )
+    , ( "A1"            , NameId    "A1"        )
+    , ( "_2X"           , NameId    "_2X"       )
+    , ( "\"\""          , StringId  ""          )
+    , ( "\"\\t\\r\\n\"" , StringId  "\\t\\r\\n" )
+    , ( ".0"            , FloatId   0.0         )
+    , ( ".123"          , FloatId   0.123       )
+    , ( "+.999"         , FloatId   0.999       )
+    , ( "-.001"         , FloatId   (-0.001)    )
+    , ( "+.001"         , FloatId   0.001       )
+    , ( "0.0"           , FloatId   0.0         )
+    , ( "1.2"           , FloatId   1.2         )
+    , ( "123.456"       , FloatId   123.456     )
+    , ( "0"             , IntegerId 0           )
+    , ( "+0"            , IntegerId 0           )
+    , ( "-0"            , IntegerId 0           )
+    , ( "123"           , IntegerId 123         )
+    , ( "-123"          , IntegerId (-123)      )
+    ]
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+
+testParser :: (Eq a, Show a) => String -> Parser a -> [(String, a)] -> IO ()
+testParser name parser tests =
+    help tests [] (0 :: Int) (0 :: Int)
+  where
+    help [] es np nf = do
+        putStrLn $ name ++ ": " ++ show np ++ " passed, " ++ show nf ++ " failed"
+        mapM_ (putStrLn . ("  "++)) (reverse es)
+        unless (null es) (putStrLn "")
+    help ((i,o):ts) es np nf =
+        case parse' parser i of
+          Left  _ -> help ts (makeFailureMessage name i o : es) np (succ nf)
+          Right v ->
+            if v /= o
+              then help ts (makeFailureMessage' name i o v : es) np (succ nf)
+              else help ts es (succ np) nf
+
+makeFailureMessage :: (Show a) => String -> String -> a -> String
+makeFailureMessage name i o =
+    "(" ++ name ++ " " ++ show i ++ ")" ++
+    " should have returned " ++ "(" ++ show o ++ ")"
+
+makeFailureMessage' :: (Show a) => String -> String -> a -> a -> String
+makeFailureMessage' name i o v =
+    "(" ++ name ++ " " ++ show i ++ ")" ++
+    " returned "  ++ "(" ++ show v ++ ")" ++
+    ", expected " ++ "(" ++ show o ++ ")"
+
+-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+
+parse' :: Parser a -> String -> Either ParseError a
+parse' p = parse p ""
+
+allCaps :: String -> [String]
+allCaps []     = [[]]
+allCaps (c:cs) =
+    concatMap (\t -> [l:t, u:t]) (allCaps cs)
+  where
+    l = toLower c
+    u = toUpper c