diff --git a/README.md b/README.md
index 1b076d6..3cf1ce2 100644
--- a/README.md
+++ b/README.md
@@ -38,3 +38,4 @@ make
 ## Tips
 
 - To update NixOS (and other inputs) run `nix flake update`
+- To autoformat the project tree using nixpkgs-fmt, run `nix fmt`.
diff --git a/flake.nix b/flake.nix
index e2050d2..8071ebe 100644
--- a/flake.nix
+++ b/flake.nix
@@ -183,6 +183,7 @@
             nodejs
           ];
         };
+        formatter = pkgs.nixpkgs-fmt;
       }
     );