diff --git a/genvalidity.cabal b/genvalidity.cabal
--- a/genvalidity.cabal
+++ b/genvalidity.cabal
@@ -1,11 +1,11 @@
--- This file has been generated from package.yaml by hpack version 0.20.0.
+-- This file has been generated from package.yaml by hpack version 0.28.2.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: dce5893ecff9eeace7dc7d30e9caa9764336390820e112683bbea5ff82892fc6
+-- hash: 75f45c202b686df17dfa4b7d2a4c2d401bb0c8e9a9437f40d008cef1de3ef380
 
 name:           genvalidity
-version:        0.5.0.3
+version:        0.5.1.0
 synopsis:       Testing utilities for the validity library
 description:    Note: There are companion instance packages for this library:
                 .
@@ -32,7 +32,8 @@
 homepage:       https://github.com/NorfairKing/validity#readme
 bug-reports:    https://github.com/NorfairKing/validity/issues
 author:         Tom Sydney Kerckhove
-maintainer:     syd.kerckhove@gmail.com
+maintainer:     syd.kerckhove@gmail.com,
+                nick.van.den.broeck666@gmail.com
 copyright:      Copyright: (c) 2016-2018 Tom Sydney Kerckhove
 license:        MIT
 license-file:   LICENSE
@@ -44,6 +45,11 @@
   location: https://github.com/NorfairKing/validity
 
 library
+  exposed-modules:
+      Data.GenValidity
+      Data.GenRelativeValidity
+  other-modules:
+      Paths_genvalidity
   hs-source-dirs:
       src
   build-depends:
@@ -52,16 +58,15 @@
     , validity >=0.5
   if impl(ghc >=8.0.0)
     ghc-options: -Wno-redundant-constraints
-  exposed-modules:
-      Data.GenValidity
-      Data.GenRelativeValidity
-  other-modules:
-      Paths_genvalidity
   default-language: Haskell2010
 
 test-suite genvalidity-test
   type: exitcode-stdio-1.0
   main-is: Spec.hs
+  other-modules:
+      Data.GenValiditySpec
+      Data.InstanceSpec
+      Paths_genvalidity
   hs-source-dirs:
       test
   ghc-options: -threaded -rtsopts -with-rtsopts=-N -Wall -fno-warn-name-shadowing
@@ -70,8 +75,4 @@
     , base
     , genvalidity
     , hspec
-  other-modules:
-      Data.GenValiditySpec
-      Data.InstanceSpec
-      Paths_genvalidity
   default-language: Haskell2010
diff --git a/src/Data/GenValidity.hs b/src/Data/GenValidity.hs
--- a/src/Data/GenValidity.hs
+++ b/src/Data/GenValidity.hs
@@ -54,6 +54,9 @@
 {-# LANGUAGE OverlappingInstances  #-}
 #define OVERLAPPING_
 #endif
+#if MIN_VERSION_base(4,9,0)
+{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
+#endif
 
 module Data.GenValidity
     ( module Data.Validity
@@ -66,16 +69,25 @@
 #if MIN_VERSION_base(4,9,0)
 import Data.List.NonEmpty (NonEmpty((:|)))
 #endif
+#if MIN_VERSION_base(4,8,0)
+import Data.Word (Word8, Word16, Word32, Word64)
+#else
 import Data.Word (Word, Word8, Word16, Word32, Word64)
-import Data.Int (Int, Int8, Int16, Int32, Int64)
+#endif
+import Data.Int (Int8, Int16, Int32, Int64)
 import Data.Ratio ((%))
 import GHC.Generics
 import GHC.Real (Ratio(..))
 
 import Test.QuickCheck hiding (Fixed)
 
+#if MIN_VERSION_base(4,8,0)
+import GHC.Natural
+import Control.Monad (forM)
+#else
 import Control.Applicative ((<*>), (<$>), pure)
 import Control.Monad (forM)
+#endif
 
 {-# ANN module "HLint: ignore Reduce duplication" #-}
 
@@ -476,24 +488,32 @@
 
 instance GenUnchecked Float where
     genUnchecked = arbitrary
+#if MIN_VERSION_QuickCheck(2,9,2)
     shrinkUnchecked = shrink
+#else
+    shrinkUnchecked _ = []
+#endif
 
 instance GenValid Float where
     genValid = arbitrary
 
 -- | Either 'NaN' or 'Infinity'.
 instance GenInvalid Float where
-    genInvalid = elements [read "NaN", read "Infinity"]
+    genInvalid = elements [read "NaN", read "Infinity", read "-Infinity", read "-0"]
 
 instance GenUnchecked Double where
     genUnchecked = arbitrary
+#if MIN_VERSION_QuickCheck(2,9,2)
     shrinkUnchecked = shrink
+#else
+    shrinkUnchecked _ = []
+#endif
 
 instance GenValid Double
 
 -- | Either 'NaN' or 'Infinity'.
 instance GenInvalid Double where
-    genInvalid = elements [read "NaN", read "Infinity"]
+    genInvalid = elements [read "NaN", read "Infinity", read "-Infinity", read "-0"]
 
 instance GenUnchecked Integer where
     genUnchecked = arbitrary
@@ -501,6 +521,16 @@
 
 instance GenValid Integer
 
+#if MIN_VERSION_base(4,8,0)
+instance GenUnchecked Natural where
+    genUnchecked = fromInteger . abs <$> genUnchecked
+    shrinkUnchecked 0 = []
+    shrinkUnchecked n = [0 .. n-1]
+
+instance GenValid Natural where
+    genValid = fromInteger . abs <$> genValid
+#endif
+
 instance (Integral a, GenUnchecked a) => GenUnchecked (Ratio a) where
     genUnchecked = do
         n <- genUnchecked
@@ -538,7 +568,7 @@
 upTo :: Int -> Gen Int
 upTo n
     | n <= 0 = pure 0
-    | otherwise = elements [0 .. n]
+    | otherwise = choose (0, n)
 
 -- | 'genSplit a' generates a tuple '(b, c)' such that 'b + c' equals 'a'.
 genSplit :: Int -> Gen (Int, Int)
@@ -583,7 +613,7 @@
 arbPartition k
     | k <= 0 = pure []
     | otherwise = do
-        first <- elements [1 .. k]
+        first <- choose (1, k)
         rest <- arbPartition $ k - first
         return $ first : rest
 
@@ -631,8 +661,7 @@
 
 instance (GUncheckedRecursivelyShrink f, GUncheckedRecursivelyShrink g) => GUncheckedRecursivelyShrink (f :*: g) where
   gUncheckedRecursivelyShrink (x :*: y) =
-      [x' :*: y | x' <- gUncheckedRecursivelyShrink x] ++
-      [x :*: y' | y' <- gUncheckedRecursivelyShrink y]
+      [x' :*: y' | x' <- gUncheckedRecursivelyShrink x, y' <- gUncheckedRecursivelyShrink y]
 
 instance (GUncheckedRecursivelyShrink f, GUncheckedRecursivelyShrink g) => GUncheckedRecursivelyShrink (f :+: g) where
   gUncheckedRecursivelyShrink (L1 x) = map L1 (gUncheckedRecursivelyShrink x)
diff --git a/test/Data/InstanceSpec.hs b/test/Data/InstanceSpec.hs
--- a/test/Data/InstanceSpec.hs
+++ b/test/Data/InstanceSpec.hs
@@ -4,7 +4,10 @@
 module Data.InstanceSpec
     ( spec
     ) where
-
+#if !MIN_VERSION_base(4,8,0)
+import Control.Applicative ((<*>), pure)
+import Data.Functor ((<$>))
+#endif
 import Data.Data
 import Data.Int
 #if MIN_VERSION_base(4,9,0)
@@ -18,9 +21,9 @@
 
 import Test.Hspec
 import Test.QuickCheck
-
-import Control.Applicative (pure)
-
+#if MIN_VERSION_base(4,8,0)
+import GHC.Natural
+#endif
 import Data.GenValidity
 
 spec :: Spec
@@ -41,26 +44,66 @@
     twoTests (Proxy :: Proxy Int64)
     twoTests (Proxy :: Proxy Integer)
     threeTests (Proxy :: Proxy Float)
+    threeTupleTests (Proxy :: Proxy Float)
     threeTests (Proxy :: Proxy Double)
-    threeTests (Proxy :: Proxy (Double, Double))
-    threeTests (Proxy :: Proxy (Double, Double, Double))
-    threeTests (Proxy :: Proxy (Double, Double, Double, Double))
-    threeTests (Proxy :: Proxy (Double, Double, Double, Double, Double))
+    threeTupleTests (Proxy :: Proxy Double)
+    threeTests (Proxy :: Proxy Rational)
+    threeTupleTests (Proxy :: Proxy Rational)
     threeTests (Proxy :: Proxy (Either Double Double))
     threeTests (Proxy :: Proxy (Maybe Double))
+    threeTests (Proxy :: Proxy (Maybe (Maybe Double)))
     threeTests (Proxy :: Proxy [Double])
     threeTests (Proxy :: Proxy (Ratio Integer))
+    threeTests (Proxy :: Proxy (Ratio Integer))
+    threeTupleTests (Proxy :: Proxy (Ratio Integer))
     threeTests (Proxy :: Proxy (Ratio Int))
+    threeTupleTests (Proxy :: Proxy (Ratio Int))
     twoTests (Proxy :: Proxy Uni)
+    twoTupleTests (Proxy :: Proxy Uni)
     twoTests (Proxy :: Proxy Deci)
+    twoTupleTests (Proxy :: Proxy Deci)
     twoTests (Proxy :: Proxy Centi)
+    twoTupleTests (Proxy :: Proxy Centi)
     twoTests (Proxy :: Proxy Milli)
+    twoTupleTests (Proxy :: Proxy Milli)
     twoTests (Proxy :: Proxy Micro)
+    twoTupleTests (Proxy :: Proxy Micro)
     twoTests (Proxy :: Proxy Nano)
+    twoTupleTests (Proxy :: Proxy Nano)
     twoTests (Proxy :: Proxy Pico)
+    twoTupleTests (Proxy :: Proxy Pico)
+#if MIN_VERSION_base(4,8,0)
+    twoTests (Proxy :: Proxy Natural)
+    
+    twoTupleTests (Proxy :: Proxy Natural)
+    
+    twoTests (Proxy :: Proxy (Ratio Integer))
+    
+    twoTupleTests (Proxy :: Proxy (Ratio Int))
+#endif
 #if MIN_VERSION_base(4,9,0)
     threeTests (Proxy :: Proxy (NonEmpty Double))
 #endif
+twoTupleTests ::
+       forall a. (Show a, Typeable a, GenValid a)
+    => Proxy a
+    -> Spec
+twoTupleTests proxy = do
+    twoTests $ (,) <$> proxy <*> proxy
+    twoTests $ (,,) <$> proxy <*> proxy <*> proxy
+    twoTests $ (,,,) <$> proxy <*> proxy <*> proxy <*> proxy
+    twoTests $ (,,,,) <$> proxy <*> proxy <*> proxy <*> proxy <*> proxy
+
+threeTupleTests ::
+       forall a. (Show a, Typeable a, GenValid a, GenInvalid a)
+    => Proxy a
+    -> Spec
+threeTupleTests proxy = do
+    threeTests $ (,) <$> proxy <*> proxy
+    threeTests $ (,,) <$> proxy <*> proxy <*> proxy
+    threeTests $ (,,,) <$> proxy <*> proxy <*> proxy <*> proxy
+    threeTests $ (,,,,) <$> proxy <*> proxy <*> proxy <*> proxy <*> proxy
+
 twoTests ::
        forall a. (Show a, Typeable a, GenValid a)
     => Proxy a