diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..4a4726a
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use_nix
diff --git a/.gitignore b/.gitignore
index 96c99b8..e90b739 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1 @@
-# avoid weird recursion problems
-.dotfiles
+.pre-commit-config.yaml
diff --git a/README.md b/README.md
index 1008cbb..f995e9b 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@ This repo stores nix to manage my machines. The initial structure was inspired b
 ```console
 $ git clone git@github.com:davegallant/nix-config.git
 $ cd nix-config
-$ sudo ./nixos-rebuild switch
+$ sudo ./nixos-rebuild.sh switch
 ```
 
 ## Update
diff --git a/default.nix b/default.nix
new file mode 100644
index 0000000..8f6fa12
--- /dev/null
+++ b/default.nix
@@ -0,0 +1,12 @@
+let
+  nix-pre-commit-hooks = import (builtins.fetchTarball
+    "https://github.com/cachix/pre-commit-hooks.nix/tarball/master");
+in {
+  pre-commit-check = nix-pre-commit-hooks.run {
+    src = ./.;
+    hooks = {
+      shellcheck.enable = true;
+      nixfmt.enable = true;
+    };
+  };
+}
diff --git a/flake.nix b/flake.nix
index 197701c..a60e177 100644
--- a/flake.nix
+++ b/flake.nix
@@ -7,62 +7,61 @@
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-20.09";
     nixpkgs-master.url = "github:NixOS/nixpkgs";
     nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
-    nixos-hardware.url = github:NixOS/nixos-hardware/master;
+    nixos-hardware.url = "github:NixOS/nixos-hardware/master";
   };
 
-  outputs = { self, home-manager, nixpkgs, nixpkgs-master, nixpkgs-unstable, nixos-hardware }: {
-    nixosConfigurations = let
-      defaultModules = [
-        home-manager.nixosModules.home-manager
-        ./modules/g810-led.nix
-        ./main/fonts.nix
-        ./main/general.nix
-        ./main/kernel.nix
-        ./main/packages.nix
-        ./main/printing.nix
+  outputs = { self, home-manager, nixpkgs, nixpkgs-master, nixpkgs-unstable
+    , nixos-hardware }: {
+      nixosConfigurations = let
+        defaultModules = [
+          home-manager.nixosModules.home-manager
+          ./modules/g810-led.nix
+          ./main/fonts.nix
+          ./main/general.nix
+          ./main/kernel.nix
+          ./main/packages.nix
+          ./main/printing.nix
 
-        ({ config, lib, lib', ... }: {
-          config = {
-            _module.args = {
-              lib' = lib // import ./lib { inherit config lib; };
-              master = lib'.pkgsImport nixpkgs-master;
-              unstable = lib'.pkgsImport nixpkgs-unstable;
+          ({ config, lib, lib', ... }: {
+            config = {
+              _module.args = {
+                lib' = lib // import ./lib { inherit config lib; };
+                master = lib'.pkgsImport nixpkgs-master;
+                unstable = lib'.pkgsImport nixpkgs-unstable;
+              };
+
+              nix.registry = {
+                nixpkgs.flake = nixpkgs;
+                nixpkgs-unstable.flake = nixpkgs-unstable;
+              };
+
+              nixpkgs.overlays = [ (import ./overlays) ];
+
+              home-manager = {
+                useGlobalPkgs = true;
+                useUserPackages = true;
+                users.dave.imports = [ ./home/default.nix ];
+              };
             };
-
-            nix.registry = {
-              nixpkgs.flake = nixpkgs;
-              nixpkgs-unstable.flake = nixpkgs-unstable;
-            };
-
-            nixpkgs.overlays = [
-              (import ./overlays)
-            ];
-
-            home-manager = {
-              useGlobalPkgs = true;
-              useUserPackages = true;
-              users.dave.imports = [ ./home/default.nix ];
-            };
-          };
-        })
-      ];
-    in {
-      hephaestus = nixpkgs.lib.nixosSystem {
-        system = "x86_64-linux";
-        modules = [
-          ./machines/hephaestus/configuration.nix
-          ./machines/hephaestus/hardware.nix
-        ] ++ defaultModules;
-      };
-      hermes = nixpkgs.lib.nixosSystem {
-        system = "x86_64-linux";
-        modules = [
-          nixos-hardware.nixosModules.lenovo-thinkpad-t480s
-          ./machines/hermes/configuration.nix
-          ./machines/hermes/hardware.nix
-        ] ++ defaultModules;
+          })
+        ];
+      in {
+        hephaestus = nixpkgs.lib.nixosSystem {
+          system = "x86_64-linux";
+          modules = [
+            ./machines/hephaestus/configuration.nix
+            ./machines/hephaestus/hardware.nix
+          ] ++ defaultModules;
+        };
+        hermes = nixpkgs.lib.nixosSystem {
+          system = "x86_64-linux";
+          modules = [
+            nixos-hardware.nixosModules.lenovo-thinkpad-t480s
+            ./machines/hermes/configuration.nix
+            ./machines/hermes/hardware.nix
+          ] ++ defaultModules;
+        };
       };
     };
-  };
 }
 
diff --git a/nixos-rebuild b/nixos-rebuild
deleted file mode 100755
index 5bd5def..0000000
--- a/nixos-rebuild
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env bash
-cd "$(dirname "$0")"
-exec nixos-rebuild -I nixos-config=machines/$(hostname)/configuration.nix "$@" --flake '.#'
diff --git a/nixos-rebuild.sh b/nixos-rebuild.sh
new file mode 100755
index 0000000..ced4a71
--- /dev/null
+++ b/nixos-rebuild.sh
@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+cd "$(dirname "$0")" || exit
+exec nixos-rebuild -I nixos-config="machines/$(hostname)/configuration.nix" "$@" --flake '.#'
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..8aa1f75
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,5 @@
+(import <nixpkgs> { }).mkShell {
+  shellHook = ''
+    ${(import ./default.nix).pre-commit-check.shellHook}
+  '';
+}