diff --git a/src/Diagrams/TwoD/Path/Turtle/Internal.hs b/src/Diagrams/TwoD/Path/Turtle/Internal.hs
index 74290a8..c5cd5e0 100644
--- a/src/Diagrams/TwoD/Path/Turtle/Internal.hs
+++ b/src/Diagrams/TwoD/Path/Turtle/Internal.hs
@@ -1,12 +1,20 @@
-{-# LANGUAGE FlexibleContexts #-}
--- | A module consisting of core types and functions to represent and operate on
+{-# LANGUAGE FlexibleContexts, TypeSynonymInstances, FlexibleInstances #-}
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Diagrams.TwoD.Path.Turtle
+-- Copyright   :  (c) 2011 Michael Sloan
+-- License     :  BSD-style (see LICENSE)
+-- Maintainer  :  Michael Sloan <mgsloan at gmail>,  Deepak Jois <deepak.jois@gmail.com>
+-- Authors     :  Michael Sloan <mgsloan at gmail>, Deepak Jois <deepak.jois@gmail.com>
+--
+-- A module consisting of core types and functions to represent and operate on
 -- a \"turtle\".
 --
 -- More info about turtle graphics:
 -- <http://en.wikipedia.org/wiki/Turtle_graphics>
 --
--- The underlying graphics primitives are provided by the diagrams library
---
+-----------------------------------------------------------------------------
+
 module Diagrams.TwoD.Path.Turtle.Internal
   (
     -- * Turtle data types and accessors
@@ -45,7 +53,7 @@ data PenStyle = PenStyle
 data TurtlePath = TurtlePath
   { penStyle    :: PenStyle        -- ^ Style
   , turtleTrail :: (P2, Trail R2)  -- ^ Path
-  }
+  } deriving Show
 
 -- | Core turtle data type. A turtle needs to keep track of its current
 -- position, like its position, heading etc., and all the paths that it has
@@ -70,7 +78,7 @@ data Turtle = Turtle
      -- | List of paths along with style information, traversed by the turtle
      -- previously
   , paths      :: [TurtlePath]
-  }
+  } deriving Show
 
 -- | Default pen style, with @penWidth@ set to 1.0 and @penColor@ set to black
 defaultPenStyle :: PenStyle
diff --git a/tests/Diagrams/TwoD/Path/Turtle/Tests.hs b/tests/Diagrams/TwoD/Path/Turtle/Tests.hs
index c3d8085..02a043f 100644
--- a/tests/Diagrams/TwoD/Path/Turtle/Tests.hs
+++ b/tests/Diagrams/TwoD/Path/Turtle/Tests.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE TypeSynonymInstances, FlexibleInstances, ViewPatterns  #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
 module Diagrams.TwoD.Path.Turtle.Tests
   ( tests
   ) where
@@ -12,8 +13,7 @@ import Test.QuickCheck
 import Diagrams.Prelude
 import Diagrams.TwoD.Path.Turtle.Internal
 
-import Debug.Trace
-
+tests :: [Test]
 tests =
   [ testProperty "Moves forward correctly" movesForward
   , testProperty "Moves backward correctly" movesBackward
@@ -27,25 +27,29 @@ tests =
 movesForward :: Turtle
              -> Property
 movesForward t =  isPenDown t ==>
-     round diffPos      == round x  -- position is set correctly
-  && round lenCurrTrail == round x  -- most recent trail has the right length
+     diffPos      == round x  -- position is set correctly
+  && lenCurrTrail == round x  -- most recent trail has the right length
  where
   x            = 2.0
   t'           = t  # forward x
-  diffPos      = magnitude $ penPos t' .-. penPos t
-  lenCurrTrail = flip arcLength 0.0001 . head . trailSegments . snd . currTrail $ t'
+  diffPos :: Int
+  diffPos      = round $ magnitude $ penPos t' .-. penPos t
+  lenCurrTrail :: Int
+  lenCurrTrail = round $ flip arcLength 0.0001 . head . trailSegments . snd . currTrail $ t'
 
 -- | The turtle moves forward by the right distance
 movesBackward :: Turtle
              -> Property
 movesBackward t =  isPenDown t ==>
-     round diffPos      == round x  -- position is set correctly
-  && round lenCurrTrail == round x  -- most recent trail has the right length
+     diffPos      == round x  -- position is set correctly
+  && lenCurrTrail == round x  -- most recent trail has the right length
  where
   x            = 2.0
   t'           = t  # backward x
-  diffPos      = magnitude $ penPos t' .-. penPos t
-  lenCurrTrail = flip arcLength 0.0001 . head . trailSegments . snd . currTrail $ t'
+  diffPos :: Int
+  diffPos      = round $ magnitude $ penPos t' .-. penPos t
+  lenCurrTrail :: Int
+  lenCurrTrail = round $ flip arcLength 0.0001 . head . trailSegments . snd . currTrail $ t'
 
 -- | The turtle moves forward and backward by the same distance and returns to
 -- the same position
@@ -104,10 +108,6 @@ trailEmptyWhenPenUp t = isPenDown t ==> trailIsEmpty
   t'           = t # penUp # forward 4 # backward 3
   trailIsEmpty = null . trailSegments . snd . currTrail $ t'
 
-instance Show Turtle where
-  show t@(Turtle a b c _ _ _) = show (a,b,c)
-
-
 -- | Arbitrary instance for the Turtle type.
 instance Arbitrary Turtle where
    arbitrary =
@@ -137,6 +137,7 @@ instance Arbitrary PenStyle where
       1 -> return $ PenStyle penWidth_  black
       2 -> return $ PenStyle penWidth_  blue
       3 -> return $ PenStyle penWidth_  brown
+      _ -> error "Should not get here"
 
 -- | Arbitrary instance of Segment
 --