diff --git a/flake.nix b/flake.nix
index 90411be..5eda977 100644
--- a/flake.nix
+++ b/flake.nix
@@ -36,7 +36,7 @@
     devShells = forAllSystems (system:
       let pkgs = pkgsFor system; in {
         default = pkgs.mkShell {
-          buildInputs = [ pkgs.go pkgs.gopls ];
+          buildInputs = [ pkgs.go pkgs.gopls pkgs.nixfmt-rfc-style ];
           # Add a Git pre-commit hook.
           shellHook = onchg.shellHook.${system};
         };