diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,72 @@
+# Changelog
+
+## [0.12.0.0] - 2021-11-20
+
+### Removed
+
+* `RelativeValidity`, it was a misfeature.
+
+## [0.11.0.0] - 2020-04-17
+
+### Changed
+
+* Made it so that Char is no longer trivially valid.
+
+## [0.10.0.0] - 2020-04-12
+
+### Changed
+
+* Made it so that Word8, Word16, Word32 and Int8, Int16, Int32 are no longer trivially valid.
+
+## [0.9.0.3] - 2020-02-10
+
+### Changed
+
+* Improved the 'validateRatioNormalised' to not crash on certain extreme values.
+
+## [0.9.0.2] - 2019-09-27
+
+### Added
+
+* `isUtf16SurrogateCodePoint` and `validateCharNotUtf16SurrogateCodePoint`
+
+### Changed
+
+* The contents of the error message when using `validateNotNan` or `validateNotInfinite` is now more accurate.
+
+### Added
+
+* `validateRatioNotNan`
+* `validateRatioNotInfinite`
+* `validateRatioNormalised`
+
+## [0.9.0.1] - 2018-12-05
+
+### Changed
+
+* The validity instance of `Ratio a` now disallows unnormalised values.
+  So `0 %: 1` is valid, but `0 %: 2` is not.
+
+## [0.9.0.0] - 2018-10-07
+
+### Added
+
+* `prettyValidate`, `validationIsValid`, `prettyValidation`
+* `validateNotNaN`, `validateNotInfinite`
+
+### Changed
+
+* Renamed `prettyValidation` to `prettyValidate` before adding the new `prettyValidation`.
+* `NaN`, `+Infinity` and `-Infinity` are now considered valid for both `Double` and `Float`.
+
+## [0.8.0.0] - 2018-08-25
+
+### Added
+* `decorateList` in `Data.Validity`
+
+### Changed
+* `-0` is now a valid value for `Double` and `Float`.
+
+## Older versions
+
+No history before version 0.8.0.0
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2016-2020 Tom Sydney Kerckhove
+Copyright (c) 2016-2021 Tom Sydney Kerckhove
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/Setup.hs b/Setup.hs
deleted file mode 100644
--- a/Setup.hs
+++ /dev/null
@@ -1,3 +0,0 @@
-import Distribution.Simple
-
-main = defaultMain
diff --git a/src/Data/RelativeValidity.hs b/src/Data/RelativeValidity.hs
deleted file mode 100644
--- a/src/Data/RelativeValidity.hs
+++ /dev/null
@@ -1,23 +0,0 @@
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE MultiParamTypeClasses #-}
-
--- | Relative validity
-module Data.RelativeValidity
-  ( RelativeValidity (..),
-    isInvalidFor,
-  )
-where
-
--- | A class of types that have additional invariants defined upon them
--- that aren't enforced by the type system
---
--- If there is a @Validity a@ instance as well, then @a `isValidFor` b@
--- should imply @isValid a@ for any @b@.
---
--- If there is a @Validity b@ instance as well, then @a `isValidFor` b@
--- should imply @isValid b@ for any @a@.
-class RelativeValidity a b where
-  isValidFor :: a -> b -> Bool
-
-isInvalidFor :: RelativeValidity a b => a -> b -> Bool
-isInvalidFor a b = not $ isValidFor a b
diff --git a/src/Data/Validity.hs b/src/Data/Validity.hs
--- a/src/Data/Validity.hs
+++ b/src/Data/Validity.hs
@@ -1,14 +1,10 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE DefaultSignatures #-}
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE TypeOperators #-}
-
-#if MIN_VERSION_base(4,9,0)
 {-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
-#endif
 
 -- |
 --
@@ -91,41 +87,24 @@
 
     -- * Re-exports
     Monoid (..),
-#if MIN_VERSION_base(4,11,0)
-    Semigroup(..),
-#endif
+    Semigroup (..),
   )
 where
 
-#if MIN_VERSION_base(4,9,0)
-import Data.List.NonEmpty (NonEmpty((:|)))
-#endif
-
-#if MIN_VERSION_base(4,8,0)
-#else
-import Data.Monoid
-import Data.Ratio
-#endif
 import Data.Bits ((.&.))
 import Data.Char (ord)
 import Data.Either (isRight)
 import Data.Fixed (Fixed (MkFixed), HasResolution)
 import Data.Int (Int64)
 import Data.List (intercalate)
+import Data.List.NonEmpty (NonEmpty ((:|)))
 import Data.Maybe (fromMaybe)
-#if MIN_VERSION_base(4,8,0)
-import GHC.Word (Word8(..), Word16(..), Word32(..), Word64(..))
-#else
-import Data.Word (Word)
-import GHC.Word (Word8(..), Word16(..), Word32(..), Word64(..))
-#endif
 import GHC.Exts (Char (..), isTrue#, leWord#, ord#, (<=#), (>=#))
 import GHC.Generics
 import GHC.Int (Int16 (..), Int32 (..), Int8 (..))
-#if MIN_VERSION_base(4,8,0)
 import GHC.Natural
-#endif
 import GHC.Real (Ratio (..))
+import GHC.Word (Word16 (..), Word32 (..), Word64 (..), Word8 (..))
 
 -- | A class of types that have additional invariants defined upon them
 
@@ -230,20 +209,12 @@
   }
   deriving (Show, Eq, Generic)
 
-#if MIN_VERSION_base(4,11,0)
 instance Semigroup Validation where
-    (Validation v1) <> (Validation v2) = Validation $ v1 ++ v2
-#endif
+  (Validation v1) <> (Validation v2) = Validation $ v1 ++ v2
 
-#if MIN_VERSION_base(4,11,0)
 instance Monoid Validation where
   mempty = Validation []
   mappend = (<>)
-#else
-instance Monoid Validation where
-  mempty = Validation []
-  mappend (Validation v1) (Validation v2) = Validation $ v1 ++ v2
-#endif
 
 -- | Declare any value to be valid in validation
 --
@@ -397,17 +368,15 @@
 instance Validity a => Validity [a] where
   validate = flip decorateList validate
 
-#if MIN_VERSION_base(4,9,0)
 -- | A nonempty list is valid if all the elements are valid.
 --
 -- See the instance for 'Validity [a]' for more information.
 instance Validity a => Validity (NonEmpty a) where
-    validate (e :| es) =
-        mconcat
-            [ annotate e "The first element of the nonempty list"
-            , annotate es "The rest of the elements of the nonempty list"
-            ]
-#endif
+  validate (e :| es) =
+    mconcat
+      [ annotate e "The first element of the nonempty list",
+        annotate es "The rest of the elements of the nonempty list"
+      ]
 
 -- | A Maybe thing is valid if the thing inside is valid or it's nothing
 -- It makes sense to assume that 'Nothing' is valid.
@@ -564,13 +533,9 @@
 instance Validity Integer where
   validate = trivialValidation
 
-#if MIN_VERSION_base(4,8,0)
 -- | Valid according to 'isValidNatural'
---
--- Only available with @base >= 4.8@.
 instance Validity Natural where
-    validate = declare "The Natural is valid." . isValidNatural
-#endif
+  validate = declare "The Natural is valid." . isValidNatural
 
 -- | Valid if the contained numbers are valid and the denominator is
 -- strictly positive.
diff --git a/test/Data/ValiditySpec.hs b/test/Data/ValiditySpec.hs
--- a/test/Data/ValiditySpec.hs
+++ b/test/Data/ValiditySpec.hs
@@ -1,16 +1,11 @@
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE MagicHash #-}
 
--- {-# LANGUAGE CPP #-}
-
 module Data.ValiditySpec
   ( spec,
   )
 where
 
--- #if !MIN_VERSION_base(4,7,0)
--- import Data.Monoid
--- #endif
 import Data.Maybe
 import Data.Validity
 import GHC.Exts (Char (..), chr#)
diff --git a/validity.cabal b/validity.cabal
--- a/validity.cabal
+++ b/validity.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           validity
-version:        0.11.0.1
+version:        0.12.0.0
 synopsis:       Validity typeclass
 description:    For more info, see <https://github.com/NorfairKing/validity the readme>.
                 .
@@ -39,6 +39,9 @@
 license:        MIT
 license-file:   LICENSE
 build-type:     Simple
+extra-source-files:
+    LICENSE
+    CHANGELOG.md
 
 source-repository head
   type: git
@@ -46,7 +49,6 @@
 
 library
   exposed-modules:
-      Data.RelativeValidity
       Data.Validity
   other-modules:
       Paths_validity
@@ -54,7 +56,7 @@
       src
   ghc-options: -Wno-redundant-constraints
   build-depends:
-      base >=4.7 && <5
+      base >=4.13 && <5
   default-language: Haskell2010
 
 test-suite validity-test
@@ -67,7 +69,7 @@
       test
   ghc-options: -threaded -rtsopts -with-rtsopts=-N -Wall
   build-depends:
-      base >=4.7 && <5
+      base >=4.13 && <5
     , hspec
     , validity
   default-language: Haskell2010