diff --git a/docs/api/context.md b/docs/api/context.md
index 684b25a..ba52f67 100644
--- a/docs/api/context.md
+++ b/docs/api/context.md
@@ -35,6 +35,8 @@ app.use(function *(){
 
   Node's `response` object.
 
+  Note: bypassing Koa's response handling and calling `res.writeHead()`, `res.write()` or `res.end()` is __not__ supported.
+
 ### ctx.request
 
   A koa `Request` object.