Typescript warnings when using interface and OpaqueToken in Angular 2 app <p>I have been following the documentation <a href="https://angular.io/docs/ts/latest/guide/dependency-injection.html#!#non-class-dependencies" rel="nofollow">here</a> and use <strong>ng-cli</strong>.</p> <p>I created the following configuration file (<strong>app-config.ts</strong>):</p> <pre><code>import { OpaqueToken } from '@angular/core'; export interface AppConfig { supportTelephoneNumber: string; } export let APP_CONFIG_t = new OpaqueToken('app.config'); export const APP_CONFIG: AppConfig = { supportTelephoneNumber: '1111 111 1111' }; </code></pre> <p>and in my <strong>app.module.ts</strong> file I have:</p> <pre><code>... @NgModule({ declarations: [ UkCurrencyPipe, AppComponent, HomeComponent ], imports: [ BrowserModule, FormsModule, HttpModule, RouterModule.forRoot(ROUTES, { useHash: true }), MaterialModule.forRoot() ], providers: [ { provide: APP_CONFIG_t, useValue: APP_CONFIG }, ... </code></pre> <p>I use this configuration in my <strong>app.component.ts</strong> file like this:</p> <pre><code>import { Component, Inject } from '@angular/core'; import { APP_CONFIG_t, AppConfig } from './app-config'; @Component({ selector: 'app-root', templateUrl: './app.component.html', styleUrls: ['./app.component.less'] }) export class AppComponent { constructor(@Inject(APP_CONFIG_t) public config: AppConfig) { callSupport(): void { window.location.href = 'tel:+' + this.config.supportTelephoneNumber; } } </code></pre> <p>When I serve my app using <strong>ng serve</strong> everything seems to work fine but I do see these warnings in the console from where I run <strong>ng server</strong>:</p> <blockquote> <p>WARNING in ./src/app/app.component.ts<br/> 40:166 export 'AppConfig' was not found in './app-config'</p> <p>WARNING in ./src/app/app.component.ts<br/> 40:195 export 'AppConfig' was not found in './app-config'</p> </blockquote> <p>Does anyone know what these warnings mean and whether or not I should worry about them?</p> <p><strong>My Versions</strong></p> <ul> <li>OS: Mac OS X El Capitan v10.11.6</li> <li>ng-cli: v1.0.0-beta.16</li> <li>angular: v2.0.1</li> <li>typescript: v2.0.2</li> </ul>