diff --git a/flake.nix b/flake.nix
index 76cb0c4..35656a7 100644
--- a/flake.nix
+++ b/flake.nix
@@ -48,6 +48,9 @@
 
     in
     {
+      formatter = forAllSystems (system:
+        nixpkgs.legacyPackages.${system}.nixpkgs-fmt);
+
       lib = {
         gen-ssh-config = import lib/gen-ssh-config.nix lib;
         ssh-keys = import lib/ssh-keys.nix;