diff --git a/genvalidity.cabal b/genvalidity.cabal
--- a/genvalidity.cabal
+++ b/genvalidity.cabal
@@ -1,13 +1,13 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.33.0.
+-- This file has been generated from package.yaml by hpack version 0.31.2.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: e90aaf1b087b8075c4ea0ebdc7a6b590389d536577d48df97509b031d9f64fcb
+-- hash: 92201210df714c4a22ab737e271cd27152fd5f43b5b83d4a0c0006a3b860b55c
 
 name:           genvalidity
-version:        0.10.0.0
+version:        0.10.0.1
 synopsis:       Testing utilities for the validity library
 description:    Note: There are companion instance packages for this library:
                 .
diff --git a/src/Data/GenValidity.hs b/src/Data/GenValidity.hs
--- a/src/Data/GenValidity.hs
+++ b/src/Data/GenValidity.hs
@@ -112,6 +112,7 @@
 import Data.Ratio ((%))
 import GHC.Generics
 import GHC.Real (Ratio(..))
+import Control.Monad (guard)
 
 import Test.QuickCheck hiding (Fixed)
 
@@ -714,8 +715,13 @@
     genValid = (do
       n <- genValid
       d <- (genValid `suchThat` (> 0))
-      pure $ n :% d) `suchThat` ((== valid) . validateRatioNormalised)
-    shrinkValid (n :% d) = filter isValid [n' % d' | (n', d') <- shrinkValid (n, d), d' > 0]
+      pure $ n :% d) `suchThat` isValid
+    shrinkValid (n :% d) = do
+      (n', d') <- shrinkValid (n, d)
+      guard $ d' > 0
+      let candidate = n' :% d'
+      guard $ isValid candidate
+      pure $ n' % d'
 
 instance (Integral a, Num a, Ord a, Validity a, GenUnchecked a) => GenInvalid (Ratio a)
 
diff --git a/test/Data/InstanceSpec.hs b/test/Data/InstanceSpec.hs
--- a/test/Data/InstanceSpec.hs
+++ b/test/Data/InstanceSpec.hs
@@ -57,6 +57,15 @@
     -- threeTupleTests (Proxy :: Proxy (Ratio Integer))
   threeTests (Proxy :: Proxy (Ratio Int))
     -- threeTupleTests (Proxy :: Proxy (Ratio Int))
+  threeTests (Proxy :: Proxy (Ratio Int8))
+  describe "shrinking (Ratio Int)" $
+    it "can shrink this example" $
+    let v = ((-9223372036854775808) % 9223372036854775761) :: Ratio Int
+     in v `notElem` shrinkValid v
+  describe "shrinking (Ratio Int8)" $
+    it "can shrink this example" $
+    let v = ((-128) % 113) :: Ratio Int8
+     in v `notElem` shrinkValid v
   twoTests (Proxy :: Proxy Uni)
   twoTupleTests (Proxy :: Proxy Uni)
   twoTests (Proxy :: Proxy Deci)
@@ -84,8 +93,7 @@
   => Proxy a
   -> Spec
 twoTupleTests proxy = do
-  modifyMaxSuccess (`quot` 2) $
-    modifyMaxSize (`quot` 2) $ twoTests $ (,) <$> proxy <*> proxy
+  modifyMaxSuccess (`quot` 2) $ modifyMaxSize (`quot` 2) $ twoTests $ (,) <$> proxy <*> proxy
 
 twoTests ::
      forall a. (Show a, Eq a, Typeable a, GenUnchecked a, GenValid a)
@@ -97,8 +105,7 @@
     genValidTest proxy
 
 threeTests ::
-     forall a.
-     (Show a, Eq a, Typeable a, GenUnchecked a, GenValid a, GenInvalid a)
+     forall a. (Show a, Eq a, Typeable a, GenUnchecked a, GenValid a, GenInvalid a)
   => Proxy a
   -> Spec
 threeTests proxy =
@@ -112,9 +119,7 @@
   => Proxy a
   -> Spec
 genUncheckedTest proxy = do
-  it
-    (unwords
-       ["genUnchecked of", nameOf proxy, "does not crash while validating"]) $
+  it (unwords ["genUnchecked of", nameOf proxy, "does not crash while validating"]) $
     forAll genUnchecked $ \a ->
       case prettyValidate (a :: a) of
         Right v -> seq v True
@@ -132,13 +137,11 @@
           Right v_ -> seq v_ $ pure () :: IO ()
           Left err -> seq err $ pure ()
   modifyMaxSuccess (`quot` 5) $
-    it
-      (unwords ["shrinkUnchecked of", nameOf proxy, "does not shrink to itself"]) $
+    it (unwords ["shrinkUnchecked of", nameOf proxy, "does not shrink to itself"]) $
     forAll genValid $ \a ->
       forM_ (shrinkUnchecked a) $ \a' ->
         unless (a /= a') $
-        expectationFailure $
-        unlines ["The value", show (a :: a), "was shrunk to itself"]
+        expectationFailure $ unlines ["The value", show (a :: a), "was shrunk to itself"]
 
 genValidTest ::
      forall a. (Show a, Eq a, Typeable a, GenValid a)
@@ -151,26 +154,20 @@
         Right v -> seq v $ pure ()
         Left err ->
           expectationFailure $
-          unlines
-            ["'validate' reported this value to be invalid:", show a, err, ""]
+          unlines ["'validate' reported this value to be invalid:", show a, err, ""]
   modifyMaxSuccess (`quot` 5) $
-    it
-      (unwords ["shrinkValid of", nameOf proxy, "shrinks to only valid values"]) $
+    it (unwords ["shrinkValid of", nameOf proxy, "shrinks to only valid values"]) $
     forAll genValid $ \a ->
       forM_ (shrinkValid a) $ \v ->
         case prettyValidate (v :: a) of
           Right v_ -> seq v_ $ pure ()
           Left err ->
             expectationFailure $
-            unlines
-              ["'validate' reported this value to be invalid:", show v, err, ""]
+            unlines ["'validate' reported this value to be invalid:", show v, err, ""]
   modifyMaxSuccess (`quot` 5) $
     it
       (unwords
-         [ "shrinkValid of"
-         , nameOf proxy
-         , "only produces values that do not crash while validating"
-         ]) $
+         ["shrinkValid of", nameOf proxy, "only produces values that do not crash while validating"]) $
     forAll genValid $ \a ->
       forM_ (shrinkValid a) $ \v ->
         case prettyValidate (v :: a) of
@@ -181,8 +178,7 @@
     forAll genValid $ \a ->
       forM_ (shrinkValid a) $ \a' ->
         unless (a /= a') $
-        expectationFailure $
-        unlines ["The value", show (a :: a), "was shrunk to itself"]
+        expectationFailure $ unlines ["The value", show (a :: a), "was shrunk to itself"]
 
 genInvalidTest ::
      forall a. (Show a, Typeable a, GenInvalid a)
@@ -193,19 +189,15 @@
     forAll genInvalid $ \a ->
       case prettyValidate (a :: a) of
         Right _ ->
-          expectationFailure $
-          unlines ["'validate' reported this value to be valid: ", show a]
+          expectationFailure $ unlines ["'validate' reported this value to be valid: ", show a]
         Left e -> seq e $ pure ()
   modifyMaxSuccess (`quot` 5) $
-    it
-      (unwords
-         ["shrinkInvalid of", nameOf proxy, "shrinks to only invalid values"]) $
+    it (unwords ["shrinkInvalid of", nameOf proxy, "shrinks to only invalid values"]) $
     forAll genInvalid $ \a ->
       forM_ (shrinkInvalid a) $ \v ->
         case prettyValidate (v :: a) of
           Right _ ->
-            expectationFailure $
-            unlines ["'validate' reported this value to be valid: ", show v]
+            expectationFailure $ unlines ["'validate' reported this value to be valid: ", show v]
           Left e -> seq e $ pure ()
   modifyMaxSuccess (`quot` 5) $
     it
@@ -218,8 +210,7 @@
       forM_ (shrinkInvalid a) $ \v ->
         case prettyValidate (v :: a) of
           Right _ ->
-            expectationFailure $
-            unlines ["'validate' reported this value to be valid: ", show v]
+            expectationFailure $ unlines ["'validate' reported this value to be valid: ", show v]
           Left e -> seq e $ pure ()
 
 nameOf ::