diff --git a/lib/middleware.js b/lib/middleware.js
index e8c6c78..e07a66b 100644
--- a/lib/middleware.js
+++ b/lib/middleware.js
@@ -120,7 +120,7 @@ const getBuiltins = (app, options) => {
         await next();
       });
 
-      app.use(convert(historyApiFallback(options.historyFallback)));
+      app.use(convert(historyApiFallback({...options.historyFallback})));
     }
   };