diff --git a/doctest/DoctestDriver.hs b/doctest/DoctestDriver.hs
new file mode 100644
--- /dev/null
+++ b/doctest/DoctestDriver.hs
@@ -0,0 +1,12 @@
+{-# LANGUAGE CPP #-}
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,4,0)
+{-# OPTIONS_GHC -F -pgmF doctest-discover #-}
+#else
+module Main where
+
+import qualified System.IO as IO
+
+main :: IO ()
+main = IO.putStrLn "WARNING: doctest will not run on GHC versions earlier than 8.4.4"
+#endif
diff --git a/hw-int.cabal b/hw-int.cabal
--- a/hw-int.cabal
+++ b/hw-int.cabal
@@ -1,67 +1,80 @@
-cabal-version:        2.2
+cabal-version: 2.2
 
-name:                 hw-int
-version:              0.0.0.4
-synopsis:             Additional facilities for Integers
-description:          Additional faciltiies for Integers. Please see README.md
-category:             Data
-stability:            Experimental
-homepage:             http://github.com/haskell-works/hw-int#readme
-bug-reports:          https://github.com/haskell-works/hw-int/issues
-author:               John Ky
-maintainer:           newhoggy@gmail.com
-copyright:            2016-2019 John Ky
-license:              BSD-3-Clause
-license-file:         LICENSE
-tested-with:          GHC == 8.8.1, GHC == 8.6.5, GHC == 8.4.4, GHC == 8.2.2
-build-type:           Simple
-extra-source-files:
-  README.md
+name:                   hw-int
+version:                0.0.1.0
+synopsis:               Additional facilities for Integers
+description:            Additional faciltiies for Integers. Please see README.md
+category:               Data
+stability:              Experimental
+homepage:               http://github.com/haskell-works/hw-int#readme
+bug-reports:            https://github.com/haskell-works/hw-int/issues
+author:                 John Ky
+maintainer:             newhoggy@gmail.com
+copyright:              2016-2020 John Ky
+license:                BSD-3-Clause
+license-file:           LICENSE
+tested-with:            GHC == 8.10.1, GHC == 8.8.3, GHC == 8.6.5, GHC == 8.4.4
+build-type:             Simple
+extra-source-files:     README.md
 
 source-repository head
   type: git
   location: https://github.com/haskell-works/hw-int
 
-common base                 { build-depends: base                 >= 4          && < 5      }
+common base                       { build-depends: base                       >= 4.11       && < 5      }
 
-common hedgehog             { build-depends: hedgehog             >= 0.6        && < 1.1    }
-common hspec                { build-depends: hspec                >= 2.7.1      && < 3      }
-common hw-hedgehog          { build-depends: hw-hedgehog          >= 0.1.0.3    && < 0.2    }
-common hw-hspec-hedgehog    { build-depends: hw-hspec-hedgehog    >= 0.1.0.7    && < 0.2    }
+common doctest                    { build-depends: doctest                    >= 0.16.2     && < 0.17   }
+common doctest-discover           { build-depends: doctest-discover           >= 0.2        && < 0.3    }
+common hedgehog                   { build-depends: hedgehog                   >= 0.6        && < 1.1    }
+common hspec                      { build-depends: hspec                      >= 2.7.1      && < 3      }
+common hw-hedgehog                { build-depends: hw-hedgehog                >= 0.1.0.3    && < 0.2    }
+common hw-hspec-hedgehog          { build-depends: hw-hspec-hedgehog          >= 0.1.0.7    && < 0.2    }
 
 common config
   default-language:     Haskell2010
   ghc-options:          -Wall -O2
 
+common hw-int
+  build-depends:        hw-int
+
 library
-  import:   base, config
-  exposed-modules:
-    HaskellWorks.Data.Int
-    HaskellWorks.Data.Int.Narrow
-    HaskellWorks.Data.Int.Narrow.Narrow16
-    HaskellWorks.Data.Int.Narrow.Narrow32
-    HaskellWorks.Data.Int.Narrow.Narrow64
-    HaskellWorks.Data.Int.Narrow.Narrow8
-    HaskellWorks.Data.Int.Widen
-    HaskellWorks.Data.Int.Widen.Widen16
-    HaskellWorks.Data.Int.Widen.Widen32
-    HaskellWorks.Data.Int.Widen.Widen64
-    HaskellWorks.Data.Int.Widen.Widen8
+  import:               base, config
+  exposed-modules:      HaskellWorks.Data.Int
+                        HaskellWorks.Data.Int.Narrow
+                        HaskellWorks.Data.Int.Narrow.Narrow16
+                        HaskellWorks.Data.Int.Narrow.Narrow32
+                        HaskellWorks.Data.Int.Narrow.Narrow64
+                        HaskellWorks.Data.Int.Narrow.Narrow8
+                        HaskellWorks.Data.Int.Widen
+                        HaskellWorks.Data.Int.Widen.Widen16
+                        HaskellWorks.Data.Int.Widen.Widen32
+                        HaskellWorks.Data.Int.Widen.Widen64
+                        HaskellWorks.Data.Int.Widen.Widen8
   other-modules:        Paths_hw_int
   autogen-modules:      Paths_hw_int
   hs-source-dirs:       src
 
 test-suite hw-int-test
-  import:   base, config
-          , hedgehog
-          , hspec
-          , hw-hedgehog
-          , hw-hspec-hedgehog
+  import:               base, config
+                      , hedgehog
+                      , hspec
+                      , hw-hedgehog
+                      , hw-hspec-hedgehog
   type:                 exitcode-stdio-1.0
   main-is:              Spec.hs
-  other-modules:        Paths_hw_int
-  autogen-modules:      Paths_hw_int
   hs-source-dirs:       test
   ghc-options:          -threaded -rtsopts -with-rtsopts=-N -Wall
   build-tool-depends:   hspec-discover:hspec-discover
   build-depends:        hw-int
+
+test-suite doctest
+  import:               base, config
+                      , doctest
+                      , doctest-discover
+                      , hw-int
+  default-language:     Haskell2010
+  type:                 exitcode-stdio-1.0
+  ghc-options:          -threaded
+  main-is:              DoctestDriver.hs
+  HS-Source-Dirs:       doctest
+  build-tool-depends:   doctest-discover:doctest-discover