diff --git a/README.md b/README.md
index 46e1653..7da4043 100644
--- a/README.md
+++ b/README.md
@@ -37,6 +37,7 @@ If you want to play offline, install all these dependencies first:
 npm install koa koa-session co-body co-views ejs
 ```
 
+Note that the exercises of kick-off are only verified under koa 1, but <strong>NOT</strong> koa 2. Meanwhile we are migrating to kao 2 and you can also take part in it.
 ## Learn More
 
  - [workshop](https://github.com/koajs/workshop) - A workshop to learn the basics of koa, Express' spiritual successor.