diff --git a/modules/legacyPackages.nix b/modules/legacyPackages.nix
index eedc075..f07ab16 100644
--- a/modules/legacyPackages.nix
+++ b/modules/legacyPackages.nix
@@ -1,43 +1,21 @@
 { config, lib, flake-parts-lib, ... }:
 let
   inherit (lib)
-    filterAttrs
-    mapAttrs
     mkOption
-    optionalAttrs
     types
     ;
   inherit (flake-parts-lib)
-    mkSubmoduleOptions
-    mkPerSystemOption
+    mkTransposedPerSystemModule
     ;
 in
-{
-  options = {
-    flake = mkSubmoduleOptions {
-      legacyPackages = mkOption {
-        type = types.lazyAttrsOf (types.lazyAttrsOf types.raw);
-        default = { };
-        description = ''
-          Per system, an attribute set of unmergeable values. This is also used by <literal>nix build .#&lt;attrpath></literal>.
-        '';
-      };
-    };
-
-    perSystem = mkPerSystemOption ({ config, ... }: {
-      options = {
-        legacyPackages = mkOption {
-          type = types.lazyAttrsOf types.raw;
-          default = { };
-          description = ''
-            An attribute set of unmergeable values. This is also used by <literal>nix build .#&lt;attrpath></literal>.
-          '';
-        };
-      };
-    });
-  };
-
-  config = {
-    transposition.legacyPackages = { };
+mkTransposedPerSystemModule {
+  name = "legacyPackages";
+  option = mkOption {
+    type = types.lazyAttrsOf types.raw;
+    default = { };
+    description = ''
+      An attribute set of unmergeable values. This is also used by <literal>nix build .#&lt;attrpath></literal>.
+    '';
   };
+  file = ./legacyPackages.nix;
 }