diff --git a/aio/content/guide/architecture.md b/aio/content/guide/architecture.md
index 06e0546314..0203cb2902 100644
--- a/aio/content/guide/architecture.md
+++ b/aio/content/guide/architecture.md
@@ -186,9 +186,9 @@ template for our `HeroListComponent`:
 
 <code-example path="architecture/src/app/hero-list.component.html" title="src/app/hero-list.component.html"></code-example>
 
-Although this template uses typical HTML elements like `<h2>` and  `<p>`, it also has some differences. Code like `*ngFor`, `{{hero.name}}`, `(click)`, `[hero]`, and `<hero-detail>` uses Angular's [template syntax](guide/template-syntax).
+Although this template uses typical HTML elements like `<h2>` and  `<p>`, it also has some differences. Code like `*ngFor`, `{{hero.name}}`, `(click)`, `[hero]`, and `<app-hero-detail>` uses Angular's [template syntax](guide/template-syntax).
 
-In the last line of the template, the `<hero-detail>` tag is a custom element that represents a new component, `HeroDetailComponent`.
+In the last line of the template, the `<app-hero-detail>` tag is a custom element that represents a new component, `HeroDetailComponent`.
 
 The `HeroDetailComponent` is a *different* component than the `HeroListComponent` you've been reviewing.
 The `HeroDetailComponent` (code not shown) presents facts about a particular hero, the
@@ -197,7 +197,7 @@ The `HeroDetailComponent` is a **child** of the `HeroListComponent`.
 
 <img src="generated/images/guide/architecture/component-tree.png" alt="Metadata" class="left">
 
-Notice how `<hero-detail>` rests comfortably among native HTML elements. Custom components mix seamlessly with native HTML in the same layouts.
+Notice how `<app-hero-detail>` rests comfortably among native HTML elements. Custom components mix seamlessly with native HTML in the same layouts.
 
 <hr class="clear"/>
 
@@ -230,8 +230,8 @@ information Angular needs to create and present the component and its view.
 Here are a few of the most useful `@Component` configuration options:
 
 * `selector`: CSS selector that tells Angular to create and insert an instance of this component
-where it finds a `<hero-list>` tag in *parent* HTML.
-For example, if an app's  HTML contains `<hero-list></hero-list>`, then
+where it finds a `<app-hero-list>` tag in *parent* HTML.
+For example, if an app's  HTML contains `<app-hero-list></app-hero-list>`, then
 Angular inserts an instance of the `HeroListComponent` view between those tags.
 
 * `templateUrl`: module-relative address of this component's HTML template, shown [above](guide/architecture#templates).