diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
new file mode 100644
index 0000000..44d3e7e
--- /dev/null
+++ b/.gitlab-ci.yml
@@ -0,0 +1,7 @@
+stages:
+  - test
+
+nixfmt:
+  stage: test
+  image: nixery.dev/shell/git/nixfmt
+  script: "nixfmt -c $(git ls-files *.nix)"