diff --git a/default.nix b/default.nix
index 97f4338..bc910f0 100644
--- a/default.nix
+++ b/default.nix
@@ -1,5 +1,5 @@
-{ pkgs ?  import <nixpkgs> {},
-  src ? ./.
+{ pkgs ? import <nixpkgs> { }
+, src ? ./.
 }:
 
 
@@ -26,7 +26,9 @@ python3.pkgs.buildPythonApplication rec {
     mypy --no-warn-unused-ignores --strict nix_update tests
   '';
   makeWrapperArgs = [
-    "--prefix PATH" ":" (lib.makeBinPath [ pkgs.nixVersions.stable or nix_2_4 nixpkgs-fmt nixpkgs-review ])
+    "--prefix PATH"
+    ":"
+    (lib.makeBinPath [ pkgs.nixVersions.stable or nix_2_4 nixpkgs-fmt nixpkgs-review ])
   ];
   shellHook = ''
     # workaround because `python setup.py develop` breaks for me
diff --git a/flake.nix b/flake.nix
index a23a874..a4b2797 100644
--- a/flake.nix
+++ b/flake.nix
@@ -6,7 +6,7 @@
 
   outputs = { self, nixpkgs, flake-utils }:
     flake-utils.lib.eachDefaultSystem (system: {
-      formatter = nixpkgs.legacyPackages.${system}.alejandra;
+      formatter = nixpkgs.legacyPackages.${system}.nixpkgs-fmt;
 
       packages = {
         default = self.packages.${system}.nix-update;
diff --git a/tests/testpkgs/default.nix b/tests/testpkgs/default.nix
index 9093521..42e0db7 100644
--- a/tests/testpkgs/default.nix
+++ b/tests/testpkgs/default.nix
@@ -1,10 +1,10 @@
-{ pkgs ? import <nixpkgs> {} }:
+{ pkgs ? import <nixpkgs> { } }:
 {
-  crate = pkgs.callPackage ./crate.nix {};
-  github = pkgs.callPackage ./github.nix {};
-  gitlab = pkgs.callPackage ./gitlab.nix {};
-  pypi = pkgs.python3.pkgs.callPackage ./pypi.nix {};
-  sourcehut = pkgs.python3.pkgs.callPackage ./sourcehut.nix {};
-  savanna = pkgs.python3.pkgs.callPackage ./savanna.nix {};
-  npm = pkgs.callPackage ./npm.nix {};
+  crate = pkgs.callPackage ./crate.nix { };
+  github = pkgs.callPackage ./github.nix { };
+  gitlab = pkgs.callPackage ./gitlab.nix { };
+  pypi = pkgs.python3.pkgs.callPackage ./pypi.nix { };
+  sourcehut = pkgs.python3.pkgs.callPackage ./sourcehut.nix { };
+  savanna = pkgs.python3.pkgs.callPackage ./savanna.nix { };
+  npm = pkgs.callPackage ./npm.nix { };
 }