diff --git a/tests/all-package-defaults.nix b/tests/all-package-defaults.nix
index 00919a4e..d51e8082 100644
--- a/tests/all-package-defaults.nix
+++ b/tests/all-package-defaults.nix
@@ -27,6 +27,10 @@ let
     # xdotool is not available on darwin
     "fontpreview"
 
+    # 2025-09-08 build failure
+    # https://github.com/NixOS/nixpkgs/pull/441063
+    "buck2"
+
     # Marked as broken
     "akku-scheme-langserver"
     "muon"