diff --git a/modules/services/home-manager-auto-expire.nix b/modules/services/home-manager-auto-expire.nix
index 467a5554..cb60417c 100644
--- a/modules/services/home-manager-auto-expire.nix
+++ b/modules/services/home-manager-auto-expire.nix
@@ -13,6 +13,17 @@ let
     path = config.programs.home-manager.path;
   };
 
+  script = pkgs.writeShellScript "home-manager-auto-expire" (
+    ''
+      echo "Expire old Home Manager generations"
+      ${homeManagerPackage}/bin/home-manager expire-generations '${cfg.timestamp}'
+    ''
+    + lib.optionalString cfg.store.cleanup ''
+      echo "Clean-up Nix store"
+      ${pkgs.nix}/bin/nix-collect-garbage ${cfg.store.options}
+    ''
+  );
+
 in
 {
   meta.maintainers = [ lib.maintainers.thiagokokada ];
@@ -89,18 +100,7 @@ in
           services.home-manager-auto-expire = {
             Unit.Description = "Home Manager expire generations";
 
-            Service.ExecStart = toString (
-              pkgs.writeShellScript "home-manager-auto-expire" (
-                ''
-                  echo "Expire old Home Manager generations"
-                  ${homeManagerPackage}/bin/home-manager expire-generations '${cfg.timestamp}'
-                ''
-                + lib.optionalString cfg.store.cleanup ''
-                  echo "Clean-up Nix store"
-                  ${pkgs.nix}/bin/nix-collect-garbage ${cfg.store.options}
-                ''
-              )
-            );
+            Service.ExecStart = toString script;
           };
         };
       })