diff --git a/dev/treefmt.nix b/dev/treefmt.nix
index e29f891..6a90a09 100644
--- a/dev/treefmt.nix
+++ b/dev/treefmt.nix
@@ -22,7 +22,8 @@
   programs.prettier.enable = true;
 
   settings.formatter = {
-    actionlint = {
+    # https://hydra.nixos.org/build/258938640
+    actionlint = pkgs.lib.mkIf (!pkgs.stdenv.isDarwin) {
       command = pkgs.actionlint;
       includes = [ ".github/workflows/*.yml" ];
     };