diff --git a/packages/examples/core/ts/metadata/directives.ts b/packages/examples/core/ts/metadata/directives.ts
index d7e63780c1..d1fa0b28aa 100644
--- a/packages/examples/core/ts/metadata/directives.ts
+++ b/packages/examples/core/ts/metadata/directives.ts
@@ -18,11 +18,11 @@ import {Component, Directive, EventEmitter} from '@angular/core';
   `
 })
 export class BankAccountComponent {
-  bankName: string;
-  id: string;
+  bankName: string|null = null;
+  id: string|null = null;
 
   // this property is not bound, and won't be automatically updated by Angular
-  normalizedBankName: string;
+  normalizedBankName: string|null = null;
 }
 
 @Component({