diff --git a/dev/treefmt.nix b/dev/treefmt.nix
index 2372dff..6aa768b 100644
--- a/dev/treefmt.nix
+++ b/dev/treefmt.nix
@@ -40,6 +40,7 @@
         "-eucx"
         ''
           ${pkgs.lib.getExe pkgs.python3.pkgs.black} "$@"
+          ${pkgs.lib.getExe pkgs.ruff} --fix "$@"
         ''
         "--" # this argument is ignored by bash
       ];
diff --git a/tests/test_eval.py b/tests/test_eval.py
index a08332e..c64c8b1 100644
--- a/tests/test_eval.py
+++ b/tests/test_eval.py
@@ -55,7 +55,8 @@ def test_flake() -> None:
 
 def test_query_cache_status() -> None:
     results = common_test(["--flake", ".#hydraJobs", "--check-cache-status"])
-    # FIXME in the nix sandbox we cannot query binary caches, this would need some local one
+    # FIXME in the nix sandbox we cannot query binary caches
+    # this would need some local one
     for result in results:
         assert "isCached" in result