diff --git a/docs/api/index.md b/docs/api/index.md
index d94b81e..7969872 100644
--- a/docs/api/index.md
+++ b/docs/api/index.md
@@ -78,6 +78,14 @@ app.listen(3000);
 const Koa = require('koa');
 const app = new Koa();
 
+// logger
+
+app.use(async (ctx, next) => {
+  await next();
+  const rt = ctx.response.get('X-Response-Time');
+  console.log(`${ctx.method} ${ctx.url} - ${rt}`);
+});
+
 // x-response-time
 
 app.use(async (ctx, next) => {
@@ -87,15 +95,6 @@ app.use(async (ctx, next) => {
   ctx.set('X-Response-Time', `${ms}ms`);
 });
 
-// logger
-
-app.use(async (ctx, next) => {
-  const start = Date.now();
-  await next();
-  const ms = Date.now() - start;
-  console.log(`${ctx.method} ${ctx.url} - ${ms}`);
-});
-
 // response
 
 app.use(async ctx => {