diff --git a/.github/workflows/nix.yml b/.github/workflows/nix.yml
index 4f38855d..3efe267c 100644
--- a/.github/workflows/nix.yml
+++ b/.github/workflows/nix.yml
@@ -24,3 +24,5 @@ jobs:
       run: nix build -L .#typhon-webapp
     - name: Run API tests
       run: nix build -L .#checks.x86_64-linux.api
+    - name: Check formatting
+      run: nix build -L .#checks.x86_64-linux.formatted
diff --git a/flake.nix b/flake.nix
index abaed563..fc3257fc 100644
--- a/flake.nix
+++ b/flake.nix
@@ -55,6 +55,7 @@
         api = pkgs.callPackage ./nix/check-api.nix {
           inherit typhon typhon-api-client-test;
         };
+        formatted = pkgs.callPackage ./nix/check-formatted.nix {inherit rustToolchain;};
         nixos = pkgs.callPackage ./nix/nixos/test.nix {typhon = self;};
       };
 
diff --git a/nix/check-formatted.nix b/nix/check-formatted.nix
new file mode 100644
index 00000000..637333a6
--- /dev/null
+++ b/nix/check-formatted.nix
@@ -0,0 +1,18 @@
+{
+  alejandra,
+  rustToolchain,
+  stdenv,
+}:
+stdenv.mkDerivation {
+  name = "formatted";
+  src = ../.;
+  nativeBuildInputs = [
+    alejandra
+    rustToolchain
+  ];
+  buildPhase = ''
+    alejandra -c .
+    cargo fmt --check
+  '';
+  installPhase = "touch $out";
+}