diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 37169526..4ac7162d 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -13,3 +13,10 @@ jobs:
     - uses: actions/checkout@v3
     - uses: cachix/install-nix-action@v22
     - run: nix flake check
+  format:
+    name: nix fmt -- --check **/*.nix
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: cachix/install-nix-action@v22
+      - run: nix fmt -- --check **/*.nix