diff --git a/step1-04/final/src/components/Counter.tsx b/step1-04/final/src/components/Counter.tsx
index 132e022..aef3799 100644
--- a/step1-04/final/src/components/Counter.tsx
+++ b/step1-04/final/src/components/Counter.tsx
@@ -1,4 +1,5 @@
 import React from 'react';
+import { Button } from './Button';
 
 export class Counter extends React.Component<any, any> {
   constructor(props) {
@@ -13,7 +14,7 @@ export class Counter extends React.Component<any, any> {
     return (
       <div>
         {text}: {clicks}
-        <button onClick={this._onButtonClick}>Click</button>
+        <Button onClick={this._onButtonClick}>Click</Button>
       </div>
     );
   }
diff --git a/step1-04/final/src/index.tsx b/step1-04/final/src/index.tsx
index 5c86c49..4035d74 100644
--- a/step1-04/final/src/index.tsx
+++ b/step1-04/final/src/index.tsx
@@ -1,4 +1,5 @@
 import React from 'react';
 import ReactDOM from 'react-dom';
+import { App } from './App';
 
-ReactDOM.render(<p>hello world </p>, document.getElementById('app'));
+ReactDOM.render(<App />, document.getElementById('app'));