diff --git a/aio/content/examples/toh-pt3/src/app/hero-detail/hero-detail.component.ts b/aio/content/examples/toh-pt3/src/app/hero-detail/hero-detail.component.ts
index 973c5b2b5a..e73308af5b 100644
--- a/aio/content/examples/toh-pt3/src/app/hero-detail/hero-detail.component.ts
+++ b/aio/content/examples/toh-pt3/src/app/hero-detail/hero-detail.component.ts
@@ -13,7 +13,7 @@ import { Hero } from '../hero';
 })
 export class HeroDetailComponent implements OnInit {
   // #docregion input-hero
-  @Input() hero: Hero;
+  @Input() hero?: Hero;
   // #enddocregion input-hero
 
   constructor() { }