diff --git a/.eslintrc.json b/.eslintrc.json
index 68e641c..01c53cf 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -3,6 +3,7 @@
     "browser": true,
     "es2021": true
   },
+  "plugins": ["react", "@typescript-eslint", "import"],
   "extends": ["plugin:react/recommended"],
   "parser": "@typescript-eslint/parser",
   "settings": {
@@ -22,6 +23,7 @@
     "ecmaVersion": 12,
     "sourceType": "module"
   },
-  "plugins": ["react", "@typescript-eslint"],
-  "rules": {}
+  "rules": {
+    "import/extensions": ["error", "always"]
+  }
 }
diff --git a/src/App.test.tsx b/src/App.test.tsx
index 2a68616..090f147 100644
--- a/src/App.test.tsx
+++ b/src/App.test.tsx
@@ -1,5 +1,7 @@
 import React from 'react';
 import { render, screen } from '@testing-library/react';
+// TODO: add extension
+// eslint-disable-next-line import/extensions
 import App from './App';
 
 test('renders learn react link', () => {
diff --git a/src/index.tsx b/src/index.tsx
index 8415a35..9552975 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -1,8 +1,12 @@
 import './index.css';
 
+// TODO: add extension
+// eslint-disable-next-line import/extensions
 import App from './App';
 import React from 'react';
 import ReactDOM from 'react-dom';
+// TODO: add extension
+// eslint-disable-next-line import/extensions
 import reportWebVitals from './reportWebVitals';
 
 ReactDOM.render(