diff --git a/genvalidity-time.cabal b/genvalidity-time.cabal
--- a/genvalidity-time.cabal
+++ b/genvalidity-time.cabal
@@ -2,10 +2,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 5a9dbd762491e40225c91e33f76c6d38d0ed5b1f6444c694732cbd9a39207d58
+-- hash: 9282d704e34c767d5dc099c5a4e4695a4d046153d553e3dab70a6c4c47db6706
 
 name:           genvalidity-time
-version:        0.2.0.0
+version:        0.2.0.1
 synopsis:       GenValidity support for time
 description:    Please see README.md
 category:       Testing
diff --git a/src/Data/GenValidity/Time/Clock.hs b/src/Data/GenValidity/Time/Clock.hs
--- a/src/Data/GenValidity/Time/Clock.hs
+++ b/src/Data/GenValidity/Time/Clock.hs
@@ -22,7 +22,8 @@
 
 instance GenUnchecked DiffTime where
     genUnchecked = picosecondsToDiffTime <$> genUnchecked
-    shrinkUnchecked = fmap fromRational . shrinkUnchecked . toRational
+    shrinkUnchecked =
+        fmap picosecondsToDiffTime . shrinkUnchecked . diffTimeToPicoseconds
 
 instance GenValid DiffTime where
     genValid = picosecondsToDiffTime <$> genValid
diff --git a/test/Data/GenValidity/TimeSpec.hs b/test/Data/GenValidity/TimeSpec.hs
--- a/test/Data/GenValidity/TimeSpec.hs
+++ b/test/Data/GenValidity/TimeSpec.hs
@@ -13,12 +13,22 @@
 spec :: Spec
 spec = do
     genValidSpec @Day
+    shrinkValidSpec @Day
     genValidSpec @UniversalTime
+    shrinkValidSpec @UniversalTime
     genValidSpec @DiffTime
+    shrinkValidSpec @DiffTime
     genValiditySpec @UTCTime
+    shrinkValiditySpec @UTCTime
     genValidSpec @NominalDiffTime
+    shrinkValidSpec @NominalDiffTime
     genValidSpec @TimeZone
+    shrinkValidSpec @TimeZone
     genValiditySpec @TimeOfDay
+    shrinkValiditySpec @TimeOfDay
     genValiditySpec @LocalTime
+    shrinkValiditySpec @LocalTime
     genValiditySpec @ZonedTime
+    shrinkValiditySpec @ZonedTime
     genValidSpec @TimeLocale
+    shrinkValidSpec @TimeLocale