diff --git a/docs/source/en/basics/service.md b/docs/source/en/basics/service.md
index a25e9beb1b..404f35941e 100644
--- a/docs/source/en/basics/service.md
+++ b/docs/source/en/basics/service.md
@@ -75,6 +75,7 @@ module.exports = app => {
 const Controller = require('egg').Controller;
 class UserController extends Controller {
   async info() {
+    const { ctx } = this;
     const userId = ctx.params.id;
     const userInfo = await ctx.service.user.find(userId);
     ctx.body = userInfo;
diff --git a/docs/source/zh-cn/basics/service.md b/docs/source/zh-cn/basics/service.md
index 608fc5b3bb..1f31689395 100644
--- a/docs/source/zh-cn/basics/service.md
+++ b/docs/source/zh-cn/basics/service.md
@@ -75,6 +75,7 @@ module.exports = app => {
 const Controller = require('egg').Controller;
 class UserController extends Controller {
   async info() {
+    const { ctx } = this;
     const userId = ctx.params.id;
     const userInfo = await ctx.service.user.find(userId);
     ctx.body = userInfo;