diff --git a/haddock-library/haddock-library.cabal b/haddock-library/haddock-library.cabal
index 44834aa9c746a8dc9231cdd938ac84efb187368a..0a07094b04ff19bcbffa1016cfbd11e114251ea3 100644
--- a/haddock-library/haddock-library.cabal
+++ b/haddock-library/haddock-library.cabal
@@ -15,7 +15,8 @@ bug-reports:          https://github.com/haskell/haddock/issues
 category:             Documentation
 build-type:           Simple
 cabal-version:        >= 2.0
-
+extra-source-files:
+  CHANGES.md
 library
   default-language:     Haskell2010
 
diff --git a/haddock-library/src/Documentation/Haddock/Markup.hs b/haddock-library/src/Documentation/Haddock/Markup.hs
index b16cf04961a3148f4084320f196b4515e4931dab..1bf6c0841bb147b7a5a6ff3ff08482125b3d40ab 100644
--- a/haddock-library/src/Documentation/Haddock/Markup.hs
+++ b/haddock-library/src/Documentation/Haddock/Markup.hs
@@ -1,4 +1,8 @@
-module Documentation.Haddock.Markup where
+-- | @since 1.4.5
+module Documentation.Haddock.Markup (
+    markup
+  , idMarkup
+  ) where
 
 import Documentation.Haddock.Types
 
diff --git a/haddock-library/src/Documentation/Haddock/Types.hs b/haddock-library/src/Documentation/Haddock/Types.hs
index 1e87edc00cb9f2913e844ff047b74c28280bfbd0..0ab6bb4c89f2b5b2cf23437518e02d7f52e6a705 100644
--- a/haddock-library/src/Documentation/Haddock/Types.hs
+++ b/haddock-library/src/Documentation/Haddock/Types.hs
@@ -81,6 +81,14 @@ data DocH mod id
   | DocHeader (Header (DocH mod id))
   deriving (Eq, Show, Functor, Foldable, Traversable)
 
+-- | 'DocMarkupH' is a set of instructions for marking up documentation.
+-- In fact, it's really just a mapping from 'Doc' to some other
+-- type [a], where [a] is usually the type of the output (HTML, say).
+-- Use 'Documentation.Haddock.Markup.markup' to apply a 'DocMarkupH' to
+-- a 'DocH'.
+--
+-- @since 1.4.5
+--
 data DocMarkupH mod id a = Markup
   { markupEmpty                :: a
   , markupString               :: String -> a