diff --git a/users/youwen/common/neovim/default.nix b/users/youwen/common/neovim/default.nix
index f0f38eb..afc4252 100644
--- a/users/youwen/common/neovim/default.nix
+++ b/users/youwen/common/neovim/default.nix
@@ -24,6 +24,9 @@
       stylua
       lua-language-server
 
+      # Haskell
+      haskellPackages.fourmolu
+
       # Misc
       codespell
       ripgrep