diff --git a/modules/angular2/core.dart b/modules/angular2/core.dart
index 1b68fa2ebc..6ce0036978 100644
--- a/modules/angular2/core.dart
+++ b/modules/angular2/core.dart
@@ -1,7 +1,7 @@
 library angular2.core;
 
 export 'package:angular2/src/core/application_tokens.dart' show APP_COMPONENT;
-export 'package:angular2/src/core/application_common.dart' show ApplicationRef;
+export 'package:angular2/src/core/application_ref.dart' show ApplicationRef;
 
 // Compiler Related Dependencies.
 export 'package:angular2/src/services/app_root_url.dart' show AppRootUrl;
diff --git a/modules/angular2/core.ts b/modules/angular2/core.ts
index f8a5b59486..9d50ec8bb0 100644
--- a/modules/angular2/core.ts
+++ b/modules/angular2/core.ts
@@ -4,8 +4,9 @@
  * Define angular core API here.
  */
 export {APP_COMPONENT} from 'angular2/src/core/application_tokens';
-export {ApplicationRef, commonBootstrap as bootstrap} from 'angular2/src/core/application_common';
+export {commonBootstrap as bootstrap} from 'angular2/src/core/application_common';
 export {Type} from 'angular2/src/facade/lang';
+export {ApplicationRef} from 'angular2/src/core/application_ref';
 
 
 // Compiler Related Dependencies.
diff --git a/modules/angular2/src/core/application.dart b/modules/angular2/src/core/application.dart
index 691fb69d45..5c9a1806f2 100644
--- a/modules/angular2/src/core/application.dart
+++ b/modules/angular2/src/core/application.dart
@@ -6,8 +6,9 @@ import 'package:angular2/src/reflection/reflection.dart' show reflector;
 import 'package:angular2/src/reflection/reflection_capabilities.dart'
     show ReflectionCapabilities;
 import 'application_common.dart';
+import 'application_ref.dart';
 
-export 'application_common.dart' show ApplicationRef;
+export 'application_ref.dart' show ApplicationRef;
 
 /// Starts an application from a root component. This implementation uses
 /// mirrors. Angular 2 transformer automatically replaces this method with a
diff --git a/modules/angular2/src/core/application.ts b/modules/angular2/src/core/application.ts
index 17eba2e993..6d4ad8a88d 100644
--- a/modules/angular2/src/core/application.ts
+++ b/modules/angular2/src/core/application.ts
@@ -1 +1,2 @@
-export {ApplicationRef, commonBootstrap as bootstrap} from './application_common';
+export {commonBootstrap as bootstrap} from './application_common';
+export {ApplicationRef} from './application_ref';
diff --git a/modules/angular2/src/core/application_common.ts b/modules/angular2/src/core/application_common.ts
index 8bd5289198..c1a5b57107 100644
--- a/modules/angular2/src/core/application_common.ts
+++ b/modules/angular2/src/core/application_common.ts
@@ -76,6 +76,7 @@ import {internalView} from 'angular2/src/core/compiler/view_ref';
 import {APP_COMPONENT_REF_PROMISE, APP_COMPONENT} from './application_tokens';
 import {wtfInit} from '../profile/wtf_init';
 import {EXCEPTION_BINDING} from './platform_bindings';
+import {ApplicationRef} from './application_ref';
 
 var _rootInjector: Injector;
 
@@ -337,51 +338,6 @@ export function commonBootstrap(
   return bootstrapProcess.promise;
 }
 
-/**
- * Represents a Angular's representation of an Application.
- *
- * `ApplicationRef` represents a running application instance. Use it to retrieve the host
- * component, injector,
- * or dispose of an application.
- */
-export class ApplicationRef {
-  _hostComponent: ComponentRef;
-  _injector: Injector;
-  _hostComponentType: Type;
-
-  /**
-   * @private
-   */
-  constructor(hostComponent: ComponentRef, hostComponentType: Type, injector: Injector) {
-    this._hostComponent = hostComponent;
-    this._injector = injector;
-    this._hostComponentType = hostComponentType;
-  }
-
-  /**
-   * Returns the current {@link ComponentMetadata} type.
-   */
-  get hostComponentType(): Type { return this._hostComponentType; }
-
-  /**
-   * Returns the current {@link ComponentMetadata} instance.
-   */
-  get hostComponent(): any { return this._hostComponent.instance; }
-
-  /**
-   * Dispose (un-load) the application.
-   */
-  dispose(): void {
-    // TODO: We also need to clean up the Zone, ... here!
-    this._hostComponent.dispose();
-  }
-
-  /**
-   * Returns the root application {@link Injector}.
-   */
-  get injector(): Injector { return this._injector; }
-}
-
 function _createAppInjector(appComponentType: Type, bindings: List<Type | Binding | List<any>>,
                             zone: NgZone): Injector {
   if (isBlank(_rootInjector)) _rootInjector = Injector.resolveAndCreate(_rootBindings);
diff --git a/modules/angular2/src/core/application_ref.ts b/modules/angular2/src/core/application_ref.ts
new file mode 100644
index 0000000000..9fcefcee50
--- /dev/null
+++ b/modules/angular2/src/core/application_ref.ts
@@ -0,0 +1,47 @@
+import {ComponentRef} from 'angular2/src/core/compiler/dynamic_component_loader';
+import {Injector} from 'angular2/di';
+import {Type} from 'angular2/src/facade/lang';
+/**
+ * Represents a Angular's representation of an Application.
+ *
+ * `ApplicationRef` represents a running application instance. Use it to retrieve the host
+ * component, injector,
+ * or dispose of an application.
+ */
+export class ApplicationRef {
+  _hostComponent: ComponentRef;
+  _injector: Injector;
+  _hostComponentType: Type;
+
+  /**
+   * @private
+   */
+  constructor(hostComponent: ComponentRef, hostComponentType: Type, injector: Injector) {
+    this._hostComponent = hostComponent;
+    this._injector = injector;
+    this._hostComponentType = hostComponentType;
+  }
+
+  /**
+   * Returns the current {@link ComponentMetadata} type.
+   */
+  get hostComponentType(): Type { return this._hostComponentType; }
+
+  /**
+   * Returns the current {@link ComponentMetadata} instance.
+   */
+  get hostComponent(): any { return this._hostComponent.instance; }
+
+  /**
+   * Dispose (un-load) the application.
+   */
+  dispose(): void {
+    // TODO: We also need to clean up the Zone, ... here!
+    this._hostComponent.dispose();
+  }
+
+  /**
+   * Returns the root application {@link Injector}.
+   */
+  get injector(): Injector { return this._injector; }
+}
diff --git a/modules/angular2/src/core/application_static.dart b/modules/angular2/src/core/application_static.dart
index 2a76cf75f2..e48cb9f345 100644
--- a/modules/angular2/src/core/application_static.dart
+++ b/modules/angular2/src/core/application_static.dart
@@ -2,6 +2,7 @@ library angular2.application_static;
 
 import 'dart:async';
 import 'application_common.dart';
+import 'application_ref.dart';
 
 /// Starts an application from a root component.
 ///
diff --git a/modules/angular2/src/web-workers/worker/application.dart b/modules/angular2/src/web-workers/worker/application.dart
index 5bb666cb84..196a6ee7fc 100644
--- a/modules/angular2/src/web-workers/worker/application.dart
+++ b/modules/angular2/src/web-workers/worker/application.dart
@@ -4,7 +4,7 @@ import "package:angular2/src/web-workers/shared/isolate_message_bus.dart";
 import "package:angular2/src/web-workers/worker/application_common.dart"
     show bootstrapWebWorkerCommon;
 import "package:angular2/src/facade/async.dart" show Future;
-import "package:angular2/src/core/application.dart" show ApplicationRef;
+import "package:angular2/src/core/application_ref.dart" show ApplicationRef;
 import "package:angular2/src/facade/lang.dart" show Type, BaseException;
 import "dart:isolate";
 import "dart:async";
diff --git a/modules/angular2/src/web-workers/worker/application.ts b/modules/angular2/src/web-workers/worker/application.ts
index 50c34e0b3f..b15b3335c8 100644
--- a/modules/angular2/src/web-workers/worker/application.ts
+++ b/modules/angular2/src/web-workers/worker/application.ts
@@ -8,7 +8,7 @@ import {Binding} from "angular2/di";
 import {Map} from 'angular2/src/facade/collection';
 import {Promise} from 'angular2/src/facade/async';
 import {bootstrapWebWorkerCommon} from "angular2/src/web-workers/worker/application_common";
-import {ApplicationRef} from "angular2/src/core/application";
+import {ApplicationRef} from "angular2/src/core/application_ref";
 import {Injectable} from "angular2/di";
 
 // TODO(jteplitz602) remove this and compile with lib.webworker.d.ts (#3492)
diff --git a/modules/angular2/src/web-workers/worker/application_common.ts b/modules/angular2/src/web-workers/worker/application_common.ts
index c52f27d716..3e70625d72 100644
--- a/modules/angular2/src/web-workers/worker/application_common.ts
+++ b/modules/angular2/src/web-workers/worker/application_common.ts
@@ -55,8 +55,7 @@ import {internalView} from 'angular2/src/core/compiler/view_ref';
 import {MessageBrokerFactory} from 'angular2/src/web-workers/worker/broker';
 import {MessageBus, MessageBusInterface} from 'angular2/src/web-workers/shared/message_bus';
 import {APP_COMPONENT_REF_PROMISE, APP_COMPONENT} from 'angular2/src/core/application_tokens';
-import {ApplicationRef} from 'angular2/src/core/application';
-import {createNgZone} from 'angular2/src/core/application_common';
+import {ApplicationRef} from 'angular2/src/core/application_ref';
 import {Serializer} from "angular2/src/web-workers/shared/serializer";
 import {ON_WEB_WORKER} from "angular2/src/web-workers/shared/api";
 import {RenderProtoViewRefStore} from 'angular2/src/web-workers/shared/render_proto_view_ref_store';
@@ -147,7 +146,7 @@ export function bootstrapWebWorkerCommon(
     componentInjectableBindings: List<Type | Binding | List<any>> = null): Promise<ApplicationRef> {
   var bootstrapProcess: PromiseCompleter<any> = PromiseWrapper.completer();
 
-  var zone = createNgZone();
+  var zone = new NgZone({enableLongStackTrace: assertionsEnabled()});
   zone.run(() => {
     // TODO(rado): prepopulate template cache, so applications with only
     // index.html and main.js are possible.