diff --git a/types/koa/koa-tests.ts b/types/koa/koa-tests.ts
index 2eff16857a..2ddf9b41e2 100644
--- a/types/koa/koa-tests.ts
+++ b/types/koa/koa-tests.ts
@@ -1,9 +1,12 @@
 import Koa = require("koa");
 
 declare module 'koa' {
-    export interface Context {
+    export interface BaseContext {
         db(): void;
     }
+    export interface Context {
+        user: {};
+    }
 }
 
 const app = new Koa();
@@ -12,6 +15,7 @@ app.context.db = () => {};
 
 app.use(async ctx => {
     console.log(ctx.db);
+    ctx.user = {};
 });
 
 app.use((ctx, next) => {