diff --git a/.github/workflows/generatemanpage.yml b/.github/workflows/generatemanpage.yml
new file mode 100644
index 0000000..40b6f4c
--- /dev/null
+++ b/.github/workflows/generatemanpage.yml
@@ -0,0 +1,33 @@
+name: Generate manpage
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Clone project
+        uses: actions/checkout@v2
+
+      - name: Install dependencies
+        run: |
+          set -ex
+          sudo apt install -y pandoc
+
+      - name: Generate manpage
+        run: |
+          set -ex
+          for d in /opt/ghc/*/bin; do PATH="$d:$PATH"; break; done
+          make -B -C man
+
+      - name: Commit/push if changed
+        run: |
+          set -ex
+          git config user.name github-actions
+          git config user.email github-actions@github.com
+          git diff --quiet --exit-code && exit
+          git commit -a -m 'man: Update'
+          git push
diff --git a/CHANGES.md b/CHANGES.md
index fa66eac..8facb97 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -37,6 +37,10 @@
 
   * Added `Foldable`, `Functor`, and `Traversable` instances for `Stack`.
 
+  * `util/GenerateManpage.hs` is no longer distributed in the tarball.
+    Instead, the manpage source is regenerated and manpage rebuilt
+    automatically in CI.
+
 ## 0.15 (September 30, 2018)
 
   * Reimplement `sendMessage` to deal properly with windowset changes made
diff --git a/cabal.project b/cabal.project
index 746035b..6015e48 100644
--- a/cabal.project
+++ b/cabal.project
@@ -2,6 +2,3 @@
 
 packages:
   xmonad.cabal
-
-package xmonad
-  flags: +generatemanpage
diff --git a/man/Makefile b/man/Makefile
new file mode 100644
index 0000000..4cef90f
--- /dev/null
+++ b/man/Makefile
@@ -0,0 +1,11 @@
+.PHONY: all
+all: xmonad.1 xmonad.1.html
+
+xmonad.1.markdown: xmonad.1.markdown.in
+	(cd .. && util/GenerateManpage.hs) <$< >$@
+
+xmonad.1: xmonad.1.markdown
+	pandoc --from=markdown --to=man --standalone --output=$@ $<
+
+xmonad.1.html: xmonad.1.markdown
+	pandoc --from=markdown --to=html --standalone --table-of-contents --output=$@ $<
diff --git a/man/xmonad.1.markdown b/man/xmonad.1.markdown.in
similarity index 100%
rename from man/xmonad.1.markdown
rename to man/xmonad.1.markdown.in
diff --git a/util/GenerateManpage.hs b/util/GenerateManpage.hs
old mode 100644
new mode 100755
index 3235757..4284cc3
--- a/util/GenerateManpage.hs
+++ b/util/GenerateManpage.hs
@@ -1,47 +1,20 @@
-{-# LANGUAGE FlexibleContexts #-}
+#!/usr/bin/env runhaskell
 
--- Generates a in-memory version of "man/xmonad.1.markdown" that has the list
--- of known key-bindings is inserted automatically from "Config.hs". That
--- document is then rendered with Pandoc as "man/xmonad.1" and
--- "man/xmonad.1.html".
+-- Reads markdown (man/xmonad.1.markdown) from stdin, subtitutes
+-- ___KEYBINDINGS___ for key-binding definitions generated from
+-- src/XMonad/Config.hs, prints result to stdout.
 --
 -- Unlike the rest of xmonad, this file is released under the GNU General
--- Public License version 2 or later.
+-- Public License version 2 or later. (Historical reasons, used to link with
+-- GPL-licensed pandoc.)
 
-import Control.Monad.IO.Class (liftIO)
 import Data.Char
 import Data.List
-import qualified Data.Text as T
-import qualified Data.Text.IO as TIO
-import Text.Pandoc
-import Text.Regex.Posix
 
 main :: IO ()
 main = do
     keybindings <- guessBindings
-
-    markdownSource <- readFile "./man/xmonad.1.markdown"
-
-    runIOorExplode $ do
-        parsed <- readMarkdown (def { readerStandalone = True, readerExtensions = pandocExtensions })
-            . T.pack
-            . unlines
-            . replace "___KEYBINDINGS___" keybindings
-            . lines
-            $ markdownSource
-
-        manTemplate <- compileDefaultTemplate (T.pack "man")
-        manBody <- writeMan def { writerTemplate = Just manTemplate } parsed
-        liftIO $ TIO.writeFile "./man/xmonad.1" $ manBody
-        liftIO $ putStrLn "Documentation created: man/xmonad.1"
-
-        htmltemplate <- compileDefaultTemplate (T.pack "html")
-        htmlBody <- writeHtml5String def
-                                     { writerTemplate = Just htmltemplate
-                                     , writerTableOfContents = True }
-                                     parsed
-        liftIO $ TIO.writeFile "./man/xmonad.1.html" htmlBody
-        liftIO $ putStrLn "Documentation created: man/xmonad.1.html"
+    interact $ unlines . replace "___KEYBINDINGS___" keybindings . lines
 
 -- | The format for the docstrings in "Config.hs" takes the following form:
 --
@@ -49,7 +22,7 @@ main = do
 --   -- mod-x %! Frob the whatsit
 -- @
 --
--- "Frob the whatsit" will be used as the description for keybinding "mod-x".--
+-- "Frob the whatsit" will be used as the description for keybinding "mod-x".
 -- If the name of the key binding is omitted, the function tries to guess it
 -- from the rest of the line. For example:
 --
@@ -61,25 +34,33 @@ main = do
 
 guessBindings :: IO String
 guessBindings = do
-  buf <- readFile "./src/XMonad/Config.hs"
-  return (intercalate "\n\n" (map markdownDefn (allBindings buf)))
+    buf <- readFile "./src/XMonad/Config.hs"
+    return (intercalate "\n\n" (map markdownDefn (allBindings buf)))
 
 allBindings :: String -> [(String, String)]
-allBindings xs = map (binding . map trim) (xs =~ "(.*)--(.*)%!(.*)")
-
-binding :: [String] -> (String, String)
-binding [ _, bindingLine, "", desc ] = (guessKeys bindingLine, desc)
-binding [ _, _, keyCombo, desc ] = (keyCombo, desc)
-binding x = error ("binding: called with unexpected argument " ++ show x)
-
-guessKeys :: String -> String
-guessKeys line =
-  case keys of
-    [key] -> concat $ intersperse "-" (modifiers ++ [map toLower key])
-    _     -> error ("guessKeys: unexpected number of keys " ++ show keys)
+allBindings = concatMap parseLine . lines
   where
-    modifiers = map (!!1) (line =~ "(mod|shift|control)Mask")
-    (_, _, _, keys) = line =~ "xK_([_[:alnum:]]+)" :: (String, String, String, [String])
+    parseLine :: String -> [(String, String)]
+    parseLine l
+        | " -- " `isInfixOf` l
+        , Just d <- parseDesc l = [(intercalate "-" (parseKeys l), d)]
+        | otherwise = []
+
+    parseDesc :: String -> Maybe String
+    parseDesc = fmap (trim . drop 4) . find (" %! " `isPrefixOf`) . tails
+
+    parseKeys :: String -> [String]
+    parseKeys l = case lex l of
+        [("", _)] -> []
+        [("--", rest)] -> case words rest of
+            k : "%!" : _ -> [k]
+            _ -> []
+        [(k, rest)] -> parseKey k ++ parseKeys rest
+
+    parseKey :: String -> [String]
+    parseKey k | "Mask" `isSuffixOf` k = [reverse (drop 4 (reverse k))]
+               | "xK_"  `isPrefixOf` k = [map toLower (drop 3 k)]
+               | otherwise             = []
 
 -- FIXME: What escaping should we be doing on these strings?
 markdownDefn :: (String, String) -> String
diff --git a/xmonad.cabal b/xmonad.cabal
index 640bb5f..5a487d5 100644
--- a/xmonad.cabal
+++ b/xmonad.cabal
@@ -43,7 +43,6 @@ extra-source-files: README.md
                     man/xmonad.1
                     man/xmonad.1.html
                     man/xmonad.hs
-                    util/GenerateManpage.hs
                     util/hpcReport.sh
 cabal-version:      >= 1.8
 
@@ -56,11 +55,6 @@ flag pedantic
   default:     False
   manual:      True
 
-flag generatemanpage
-  default:     False
-  manual:      True
-  description: Build the tool for generating the man page
-
 flag quickcheck-classes
 
 library
@@ -107,15 +101,6 @@ executable xmonad
   if flag(pedantic)
     ghc-options:   -Werror
 
-executable generatemanpage
-  main-is:        GenerateManpage.hs
-  hs-source-dirs: util
-
-  if flag(generatemanpage)
-    build-depends: base, pandoc > 2.10, regex-posix, text
-  else
-    buildable: False
-
 test-suite properties
   type:           exitcode-stdio-1.0
   main-is:        Properties.hs