diff --git a/ascii-group.cabal b/ascii-group.cabal
--- a/ascii-group.cabal
+++ b/ascii-group.cabal
@@ -1,11 +1,14 @@
-cabal-version: 2.0
+cabal-version: 3.0
 
 name: ascii-group
-version: 1.0.0.10
+version: 1.0.0.12
 synopsis: ASCII character groups
 category: Data, Text
 
-description: This package defines a @Group@ type that describes the two varieties of ASCII character, and provides some functions for classifying characters by group.
+description:
+    This package defines a @Group@ type that describes
+    the two varieties of ASCII character, and provides
+    some functions for classifying characters by group.
 
 license: Apache-2.0
 license-file: license.txt
@@ -13,42 +16,54 @@
 author: Chris Martin
 maintainer: Chris Martin, Julie Moronuki
 
-homepage:    https://github.com/typeclasses/ascii
+homepage: https://github.com/typeclasses/ascii
 bug-Reports: https://github.com/typeclasses/ascii/issues
 
 build-type: Simple
 
-extra-source-files: changelog.txt
-
 source-repository head
-    type:     git
+    type: git
     location: git://github.com/typeclasses/ascii.git
 
-library
+common base
     default-language: Haskell2010
-    default-extensions: NoImplicitPrelude
-    default-extensions: StandaloneDeriving
-    default-extensions: DeriveAnyClass
-    default-extensions: DerivingStrategies
-    default-extensions: DeriveDataTypeable
-    default-extensions: DeriveGeneric
     ghc-options: -Wall
+
+    default-extensions:
+        NoImplicitPrelude
+
+    build-depends:
+        ascii-char ^>= 1.0
+      , base >= 4.11 && < 4.17
+
+library
+    import: base
     hs-source-dirs: library
 
-    build-depends: ascii-char ^>= 1.0
+    default-extensions:
+        DeriveAnyClass
+        DeriveDataTypeable
+        DeriveGeneric
+        DerivingStrategies
+        StandaloneDeriving
 
-    build-depends: base       >= 4.11 && < 4.17
-    build-depends: hashable   >= 1.2  && < 1.5
+    build-depends:
+        hashable >= 1.2 && < 1.5
 
-    exposed-modules: ASCII.Group
+    exposed-modules:
+        ASCII.Group
 
-test-suite test
+test-suite test-ascii-group
+    import: base
     type: exitcode-stdio-1.0
-    default-language: Haskell2010
-    default-extensions: NoImplicitPrelude
-    default-extensions: OverloadedStrings
-    default-extensions: QuasiQuotes
-    ghc-options: -Wall
     hs-source-dirs: test
-    main-is: test.hs
-    build-depends: ascii-char, ascii-group, base
+    main-is: Main.hs
+
+    build-depends:
+        ascii-group
+      , hedgehog ^>= 1.0 || ^>= 1.1
+
+    default-extensions:
+        OverloadedStrings
+        QuasiQuotes
+        TemplateHaskell
diff --git a/changelog.txt b/changelog.txt
deleted file mode 100644
--- a/changelog.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-1.0.0.0  - 2020-05-05 - Initial release
-1.0.0.2  - 2020-05-18 - Support GHC 8.10
-1.0.0.4  - 2021-02-10 - Support GHC 9.0
-1.0.0.6  - 2021-09-26 - Add a test suite
-1.0.0.8  - 2021-11-13 - Support hashable 1.4
-1.0.0.10 - 2022-01-09 - Support GHC 9.2
diff --git a/library/ASCII/Group.hs b/library/ASCII/Group.hs
--- a/library/ASCII/Group.hs
+++ b/library/ASCII/Group.hs
@@ -12,15 +12,15 @@
   )
   where
 
-import ASCII.Char    ( Char )
-import Data.Bool     ( Bool )
-import Data.Data     ( Data )
-import Data.Eq       ( Eq, (==) )
-import Data.Hashable ( Hashable )
-import Data.Ord      ( Ord, (<) )
-import GHC.Generics  ( Generic )
-import Prelude       ( Enum, Bounded )
-import Text.Show     ( Show )
+import ASCII.Char (Char)
+import Data.Bool (Bool)
+import Data.Data (Data)
+import Data.Eq (Eq, (==))
+import Data.Hashable (Hashable)
+import Data.Ord (Ord, (<))
+import GHC.Generics (Generic)
+import Prelude (Bounded, Enum)
+import Text.Show (Show)
 
 import qualified ASCII.Char as Char
 
diff --git a/test/Main.hs b/test/Main.hs
new file mode 100644
--- /dev/null
+++ b/test/Main.hs
@@ -0,0 +1,64 @@
+module Main (main) where
+
+import ASCII.Group
+
+import ASCII.Char (Char (..), allCharacters)
+
+import Control.Monad (Monad (..))
+import Data.Bool (not)
+import Data.Foldable (all)
+import Data.Function (($))
+import Data.List (filter, length)
+import System.IO (IO)
+import Control.Monad (when)
+import System.Exit (exitFailure)
+
+import Hedgehog (Property, assert, checkParallel, discover, property,
+                 withTests, (===))
+
+main :: IO ()
+main = checkParallel $$(discover) >>= \ok -> when (not ok) exitFailure
+
+prop_letter :: Property
+prop_letter = withTests 1 $ property $
+    charGroup CapitalLetterA === Printable
+
+prop_control :: Property
+prop_control = withTests 1 $ property $
+    charGroup EndOfTransmission === Control
+
+prop_not_printable :: Property
+prop_not_printable = withTests 1 $ property $
+    assert $ not $ inGroup Printable EndOfTransmission
+
+prop_is_control :: Property
+prop_is_control = withTests 1 $ property $
+    assert $ inGroup Control EndOfTransmission
+
+-- It is perhaps surprising that space is considered a
+-- "printable" character, since it does not visibly appear.
+prop_space_is_printable :: Property
+prop_space_is_printable = withTests 1 $ property $
+    charGroup Space === Printable
+
+-- It is perhaps surprising that horizontal tab is not
+-- in the same category as space.
+prop_horizontal_tab_is_control :: Property
+prop_horizontal_tab_is_control = withTests 1 $ property $
+    charGroup HorizontalTab === Control
+
+prop_various_printables :: Property
+prop_various_printables = withTests 1 $ property $
+    assert $ all (inGroup Printable) [CapitalLetterA, SmallLetterZ, Digit4, Tilde]
+
+prop_various_controls :: Property
+prop_various_controls = withTests 1 $ property $
+    assert $ all (inGroup Control) [Null, Substitute, UnitSeparator, Delete]
+
+prop_count_printables :: Property
+prop_count_printables = withTests 1 $ property $
+    length (filter (inGroup Printable) allCharacters) === 95
+
+prop_count_controls :: Property
+prop_count_controls = withTests 1 $ property $
+    length (filter (inGroup Control) allCharacters) === 33
diff --git a/test/test.hs b/test/test.hs
deleted file mode 100644
--- a/test/test.hs
+++ /dev/null
@@ -1,57 +0,0 @@
-module Main where
-
-import ASCII.Group
-
-import ASCII.Char (Char (..), allCharacters)
-
-import Control.Applicative (Applicative (..))
-import Control.Monad (Monad (..))
-import Data.Bool (Bool (..), not)
-import Data.Eq (Eq ((==)))
-import Data.Foldable (all)
-import Data.Function ((.), ($))
-import Data.Functor (Functor (..))
-import Data.List (intercalate, map, null, length, filter)
-import Data.Semigroup ((<>))
-import Numeric.Natural (Natural)
-import System.Exit (die)
-import System.IO (IO, putStrLn)
-import Text.Show (show)
-
-main :: IO ()
-main = dieIfFailures $ do
-    test 1 $ map charGroup [CapitalLetterA, EndOfTransmission] == [Printable, Control]
-    test 2 $ not $ inGroup Printable EndOfTransmission
-    test 3 $ inGroup Control EndOfTransmission
-    test 4 $ charGroup Space == Printable
-    test 5 $ charGroup HorizontalTab == Control
-    test 6 $ all (inGroup Printable) [CapitalLetterA, SmallLetterZ, Digit4, Tilde]
-    test 7 $ all (inGroup Control) [Null, Substitute, UnitSeparator, Delete]
-    test 8 $ length (filter (inGroup Control) allCharacters) == 33
-    test 9 $ length (filter (inGroup Printable) allCharacters) == 95
-
-dieIfFailures :: Failures a -> IO a
-dieIfFailures (Failures fs x) =
-    if null fs
-        then do putStrLn "💯"; return x
-        else die $ intercalate " " (map (("🔥" <> ) . show) fs)
-
-type TestNumber = Natural
-
-test :: TestNumber -> Bool -> Failures ()
-test n t = Failures (if t then [] else [n]) ()
-
-data Failures a = Failures [TestNumber] a
-
-instance Functor Failures
-  where
-    fmap f (Failures a x) = Failures a (f x)
-
-instance Applicative Failures
-  where
-    pure x = Failures [] x
-    Failures a f <*> Failures b x = Failures (a <> b) (f x)
-
-instance Monad Failures
-  where
-    Failures a x >>= f = let Failures b y = f x in Failures (a <> b) y