diff --git a/Data/Convertible/Instances/String.hs b/Data/Convertible/Instances/String.hs
--- a/Data/Convertible/Instances/String.hs
+++ b/Data/Convertible/Instances/String.hs
@@ -42,15 +42,14 @@
 import qualified Data.Text.Lazy as LT
 
 import Data.Time.Calendar
+import Data.Ratio
 
 #if TEST
 import Test.Framework (testGroup, Test)
 --import Test.Framework.Providers.HUnit
-import Test.Framework.Providers.QuickCheck (testProperty)
+import Test.Framework.Providers.QuickCheck2 (testProperty)
 --import Test.HUnit hiding (Test, path)
-import Test.QuickCheck
 import Data.Char (isDigit)
-import Data.Ratio ((%))
 #endif
 
 $(deriveAttempts
@@ -147,19 +146,13 @@
 
 -- Rational
 instance ConvertSuccess Rational [Char] where
-    convertSuccess = show . (fromRational :: Rational -> Double)
+    convertSuccess r
+        | denominator r == 1 = show $ numerator r
+        | otherwise = show $ (fromRational r :: Double)
 instance ConvertAttempt [Char] Rational where
     convertAttempt = fmap realToFrac . (SF.read :: String -> Attempt Double)
 
 #if TEST
-instance Arbitrary Rational where
-    coarbitrary = undefined
-    arbitrary = do
-        n <- arbitrary
-        d' <- arbitrary
-        let d =  if d' == 0 then 1 else d'
-        return (n % d)
-
 propRationalId :: Rational -> Bool
 propRationalId r = convertAttempt (convertSuccess r :: String) `almostEquals` r
 
@@ -244,5 +237,14 @@
 testSuite = testGroup "Data.Convertible.Instances.String"
     [ testProperty "propRationalId" propRationalId
     , testProperty "propRationalAllDigits" propRationalAllDigits
+    , testProperty "propRationalAllNums" propRationalAllNums
     ]
+
+propRationalAllNums :: Integer -> Bool
+propRationalAllNums i = go (i % 1) where
+  go :: Rational -> Bool
+  go r
+    | r < 0 = go $ negate r
+    | otherwise = all isDigit $ cs r
+
 #endif
diff --git a/convertible-text.cabal b/convertible-text.cabal
--- a/convertible-text.cabal
+++ b/convertible-text.cabal
@@ -1,5 +1,5 @@
 Name: convertible-text
-Version: 0.2.0.3
+Version: 0.2.0.4
 License: LGPL
 Maintainer: Michael Snoyman <michael@snoyman.com>
 Author: John Goerzen, Michael Snoyman
@@ -70,10 +70,10 @@
         Buildable: True
         cpp-options:     -DTEST
         build-depends:   test-framework,
-                         test-framework-quickcheck,
+                         test-framework-quickcheck2,
                          test-framework-hunit,
                          HUnit,
-                         QuickCheck >= 1 && < 2
+                         QuickCheck >= 2 && < 3
     else
         Buildable: False
     ghc-options:     -Wall