diff --git a/flake.lock b/flake.lock
index 8f3c38c..5e12936 100644
--- a/flake.lock
+++ b/flake.lock
@@ -7,11 +7,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1719994518,
-        "narHash": "sha256-pQMhCCHyQGRzdfAkdJ4cIWiw+JNuWsTX7f0ZYSyz0VY=",
+        "lastModified": 1726153070,
+        "narHash": "sha256-HO4zgY0ekfwO5bX0QH/3kJ/h4KvUDFZg8YpkNwIbg1U=",
         "owner": "hercules-ci",
         "repo": "flake-parts",
-        "rev": "9227223f6d922fee3c7b190b2cc238a99527bbb7",
+        "rev": "bcef6817a8b2aa20a5a6dbb19b43e63c5bf8619a",
         "type": "github"
       },
       "original": {
@@ -22,11 +22,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1720181791,
-        "narHash": "sha256-i4vJL12/AdyuQuviMMd1Hk2tsGt02hDNhA0Zj1m16N8=",
+        "lastModified": 1727429674,
+        "narHash": "sha256-2/wcpn7a8xEx/c1/ih1DHTyVLOUME7xLRfi0mOBT35s=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "4284c2b73c8bce4b46a6adf23e16d9e2ec8da4bb",
+        "rev": "e0f477a570df7375172a08ddb9199c90853c63f0",
         "type": "github"
       },
       "original": {
@@ -50,11 +50,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1719887753,
-        "narHash": "sha256-p0B2r98UtZzRDM5miGRafL4h7TwGRC4DII+XXHDHqek=",
+        "lastModified": 1727431250,
+        "narHash": "sha256-uGRlRT47ecicF9iLD1G3g43jn2e+b5KaMptb59LHnvM=",
         "owner": "numtide",
         "repo": "treefmt-nix",
-        "rev": "bdb6355009562d8f9313d9460c0d3860f525bc6c",
+        "rev": "879b29ae9a0378904fbbefe0dadaed43c8905754",
         "type": "github"
       },
       "original": {
diff --git a/treefmt.nix b/treefmt.nix
index 587e79c..e5b57ee 100644
--- a/treefmt.nix
+++ b/treefmt.nix
@@ -33,7 +33,7 @@
           options = [
             "-eucx"
             ''
-              ${lib.getExe pkgs.ruff} --fix "$@"
+              ${lib.getExe pkgs.ruff} check "$@"
               ${lib.getExe pkgs.ruff} format "$@"
             ''
             "--" # this argument is ignored by bash