diff --git a/packages/ember-application/lib/system/application.js b/packages/ember-application/lib/system/application.js
index 3e7dbde685c..473ed979743 100644
--- a/packages/ember-application/lib/system/application.js
+++ b/packages/ember-application/lib/system/application.js
@@ -37,7 +37,7 @@ import LegacyEachView from 'ember-views/views/legacy_each_view';
 import LinkToComponent from 'ember-routing-views/views/link';
 import RoutingService from 'ember-routing/services/routing';
 import ContainerDebugAdapter from 'ember-extension-support/container_debug_adapter';
-
+import { _loaded } from 'ember-runtime/system/lazy_load';
 import environment from 'ember-metal/environment';
 
 function props(obj) {
@@ -772,6 +772,10 @@ var Application = Namespace.extend({
     this._bootPromise = null;
     this._bootResolver = null;
 
+    if (_loaded.application === this) {
+      _loaded.application = undefined;
+    }
+
     if (this.__deprecatedInstance__) {
       this.__deprecatedInstance__.destroy();
     }
diff --git a/packages/ember-application/tests/system/application_test.js b/packages/ember-application/tests/system/application_test.js
index 205c78ac075..fbe44e2383a 100644
--- a/packages/ember-application/tests/system/application_test.js
+++ b/packages/ember-application/tests/system/application_test.js
@@ -12,6 +12,7 @@ import EmberObject from 'ember-runtime/system/object';
 import EmberRoute from 'ember-routing/system/route';
 import jQuery from 'ember-views/system/jquery';
 import compile from 'ember-template-compiler/system/compile';
+import { _loaded } from 'ember-runtime/system/lazy_load';
 
 var trim = jQuery.trim;
 
@@ -332,3 +333,11 @@ QUnit.test('registers controls onto to container', function() {
 
   ok(app.__container__.lookup('view:select'), 'Select control is registered into views');
 });
+
+QUnit.test('does not leak itself in onLoad._loaded', function() {
+  equal(_loaded.application, undefined);
+  var app = run(Application, 'create');
+  equal(_loaded.application, app);
+  run(app, 'destroy');
+  equal(_loaded.application, undefined);
+});
diff --git a/packages/ember-runtime/lib/system/lazy_load.js b/packages/ember-runtime/lib/system/lazy_load.js
index d98ceaef9f9..6de926c5069 100644
--- a/packages/ember-runtime/lib/system/lazy_load.js
+++ b/packages/ember-runtime/lib/system/lazy_load.js
@@ -10,6 +10,7 @@ import 'ember-runtime/system/native_array'; // make sure Ember.A is setup.
 
 var loadHooks = Ember.ENV.EMBER_LOAD_HOOKS || {};
 var loaded = {};
+export var _loaded = loaded;
 
 /**
   Detects when a specific package of Ember (e.g. 'Ember.Application')
@@ -31,12 +32,12 @@ var loaded = {};
   @private
 */
 export function onLoad(name, callback) {
-  var object;
+  var object = loaded[name];
 
   loadHooks[name] = loadHooks[name] || Ember.A();
   loadHooks[name].pushObject(callback);
 
-  if (object = loaded[name]) {
+  if (object) {
     callback(object);
   }
 }
diff --git a/packages/ember-testing/lib/test.js b/packages/ember-testing/lib/test.js
index a00a5db6738..5e87f2c05bb 100644
--- a/packages/ember-testing/lib/test.js
+++ b/packages/ember-testing/lib/test.js
@@ -453,6 +453,7 @@ EmberApplication.reopen({
 
     for (var name in helpers) {
       this.helperContainer[name] = this.originalMethods[name];
+      delete Test.Promise.prototype[name];
       delete this.testHelpers[name];
       delete this.originalMethods[name];
     }
diff --git a/packages/ember-testing/tests/helpers_test.js b/packages/ember-testing/tests/helpers_test.js
index 56f4e4007f8..1b52661c6da 100644
--- a/packages/ember-testing/tests/helpers_test.js
+++ b/packages/ember-testing/tests/helpers_test.js
@@ -99,17 +99,28 @@ QUnit.module('ember-testing: Helper setup', {
   teardown() { cleanup(); }
 });
 
+function registerHelper() {
+  Test.registerHelper('LeakyMcLeakLeak', function(app) {
+  });
+}
+
 QUnit.test('Ember.Application#injectTestHelpers/#removeTestHelpers', function() {
   App = run(EmberApplication, EmberApplication.create);
   assertNoHelpers(App);
 
+  registerHelper();
+
   App.injectTestHelpers();
   assertHelpers(App);
+  ok(Ember.Test.Promise.prototype.LeakyMcLeakLeak, 'helper in question SHOULD be present');
 
   App.removeTestHelpers();
   assertNoHelpers(App);
+
+  equal(Ember.Test.Promise.prototype.LeakyMcLeakLeak, undefined, 'should NOT leak test promise extensions');
 });
 
+
 QUnit.test('Ember.Application#setupForTesting', function() {
   run(function() {
     App = EmberApplication.create();