diff --git a/README.md b/README.md
index 19ed576f..09e71607 100644
--- a/README.md
+++ b/README.md
@@ -87,6 +87,7 @@ eval "$shellHook"
 ## Haskell
 
 - [ormolu](https://github.com/tweag/ormolu)
+- [fourmolu](https://github.com/parsonsmatt/fourmolu)
 - [hindent](https://github.com/chrisdone/hindent)
 - [stylish-haskell](https://github.com/jaspervdj/stylish-haskell)
 - [hlint](https://github.com/ndmitchell/hlint)
diff --git a/modules/hooks.nix b/modules/hooks.nix
index f132cbf1..57b829f0 100644
--- a/modules/hooks.nix
+++ b/modules/hooks.nix
@@ -87,6 +87,16 @@ in
             }";
           files = "\\.l?hs$";
         };
+      fourmolu =
+        {
+          name = "fourmolu";
+          description = "Haskell code prettifier.";
+          entry =
+            "${tools.fourmolu}/bin/fourmolu --mode inplace ${
+            lib.escapeShellArgs (lib.concatMap (ext: [ "--ghc-opt" "-X${ext}" ]) settings.ormolu.defaultExtensions)
+            }";
+          files = "\\.l?hs$";
+        };
       hindent =
         {
           name = "hindent";
diff --git a/nix/tools.nix b/nix/tools.nix
index 487ac13d..3a4f00fa 100644
--- a/nix/tools.nix
+++ b/nix/tools.nix
@@ -27,7 +27,7 @@
 {
   inherit ansible-lint hlint shellcheck ormolu hindent cabal-fmt nixpkgs-fmt nixfmt nix-linter rustfmt clippy cargo;
   inherit (elmPackages) elm-format;
-  inherit (haskellPackages) stylish-haskell brittany hpack;
+  inherit (haskellPackages) stylish-haskell brittany hpack fourmolu;
   inherit (pythonPackages) yamllint;
   inherit (nodePackages) prettier;
   purty = callPackage ./purty { purty = nodePackages.purty; };