diff --git a/flake.nix b/flake.nix
index 08652be..705ee7e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -43,6 +43,10 @@
         # Apply post-flakeparts massaging for limited supported systems, e.g. systems for which
         # we don't have KVM support and cannot test in CI, but we still can meaningfully
         # build packages.
+        {
+          path = [ "legacyPackages" "unsupportedChecks" ];
+          update = checks: checks // (nixpkgs.lib.filterAttrs (name: _: !builtins.elem name supportedSystems) outputs.checks);
+        }
         {
           path = [ "checks" ];
           update = nixpkgs.lib.filterAttrs (name: _: builtins.elem name supportedSystems);