diff --git a/docs/advanced/Middleware.md b/docs/advanced/Middleware.md
index 1c5f344169..31f1d8bf3c 100644
--- a/docs/advanced/Middleware.md
+++ b/docs/advanced/Middleware.md
@@ -253,7 +253,7 @@ Instead of `applyMiddlewareByMonkeypatching()`, we could write `applyMiddleware(
 function applyMiddleware(store, middlewares) {
   middlewares = middlewares.slice()
   middlewares.reverse()
-  const dispatch = store.dispatch
+  let dispatch = store.dispatch
   middlewares.forEach(middleware =>
     dispatch = middleware(store)(dispatch)
   )