diff --git a/Chapter07/error-boundaries/src/UserList.js b/Chapter07/error-boundaries/src/UserList.js
index 31b444cee..3fee7cbe9 100644
--- a/Chapter07/error-boundaries/src/UserList.js
+++ b/Chapter07/error-boundaries/src/UserList.js
@@ -7,7 +7,7 @@ export default ({ error, loading, users }) => (
     <LoadingMessage loading={loading} />
     <ul>
       {users.map(user => (
-        <li key={user.id.toUpperCase()}>{user.name}</li>
+        <li key={user.id}>{user.name}</li>
       ))}
     </ul>
   </section>