diff --git a/packages/core/src/testability/testability.ts b/packages/core/src/testability/testability.ts
index f007707880..f39e0bb823 100644
--- a/packages/core/src/testability/testability.ts
+++ b/packages/core/src/testability/testability.ts
@@ -98,22 +98,13 @@ export class Testability implements PublicTestability {
   /** @internal */
   _runCallbacksIfReady(): void {
     if (this.isStable()) {
-      if (this._callbacks.length !== 0) {
-        // Schedules the call backs after a macro task run outside of the angular zone to make sure
-        // no new task are added
-        this._ngZone.runOutsideAngular(() => {
-          setTimeout(() => {
-            if (this.isStable()) {
-              while (this._callbacks.length !== 0) {
-                (this._callbacks.pop() !)(this._didWork);
-              }
-              this._didWork = false;
-            }
-          });
-        });
-      } else {
+      // Schedules the call backs in a new frame so that it is always async.
+      scheduleMicroTask(() => {
+        while (this._callbacks.length !== 0) {
+          (this._callbacks.pop() !)(this._didWork);
+        }
         this._didWork = false;
-      }
+      });
     } else {
       // Not Ready
       this._didWork = true;
diff --git a/packages/core/test/testability/testability_spec.ts b/packages/core/test/testability/testability_spec.ts
index ec5deb1af9..ee5e7560c5 100644
--- a/packages/core/test/testability/testability_spec.ts
+++ b/packages/core/test/testability/testability_spec.ts
@@ -16,11 +16,13 @@ import {scheduleMicroTask} from '../../src/util';
 
 
 
-// Schedules a task to be run after Testability checks for oustanding tasks. Since Testability
-// uses a 0 second timeout to check for outstanding tasks we add our 0 second timeout after a
-// micro task (which ensures Testability's timeout is run first).
-function afterTestabilityCheck(fn: Function): void {
-  scheduleMicroTask(() => setTimeout(fn));
+// Schedules a microtasks (using a resolved promise .then())
+function microTask(fn: Function): void {
+  scheduleMicroTask(() => {
+    // We do double dispatch so that we  can wait for scheduleMicrotask in the Testability when
+    // NgZone becomes stable.
+    scheduleMicroTask(fn);
+  });
 }
 
 @Injectable()
@@ -63,7 +65,7 @@ class MockNgZone extends NgZone {
       it('should fire whenstable callbacks if pending count is 0',
          inject([AsyncTestCompleter], (async: AsyncTestCompleter) => {
            testability.whenStable(execute);
-           afterTestabilityCheck(() => {
+           microTask(() => {
              expect(execute).toHaveBeenCalled();
              async.done();
            });
@@ -80,11 +82,11 @@ class MockNgZone extends NgZone {
            testability.increasePendingRequestCount();
            testability.whenStable(execute);
 
-           afterTestabilityCheck(() => {
+           microTask(() => {
              expect(execute).not.toHaveBeenCalled();
              testability.decreasePendingRequestCount();
 
-             afterTestabilityCheck(() => {
+             microTask(() => {
                expect(execute).not.toHaveBeenCalled();
                async.done();
              });
@@ -96,11 +98,11 @@ class MockNgZone extends NgZone {
            testability.increasePendingRequestCount();
            testability.whenStable(execute);
 
-           afterTestabilityCheck(() => {
+           microTask(() => {
              expect(execute).not.toHaveBeenCalled();
              testability.decreasePendingRequestCount();
 
-             afterTestabilityCheck(() => {
+             microTask(() => {
                expect(execute).toHaveBeenCalled();
                async.done();
              });
@@ -118,7 +120,7 @@ class MockNgZone extends NgZone {
       it('should fire whenstable callbacks with didWork if pending count is 0',
          inject([AsyncTestCompleter], (async: AsyncTestCompleter) => {
            testability.whenStable(execute);
-           afterTestabilityCheck(() => {
+           microTask(() => {
              expect(execute).toHaveBeenCalledWith(false);
              async.done();
            });
@@ -129,14 +131,14 @@ class MockNgZone extends NgZone {
            testability.increasePendingRequestCount();
            testability.whenStable(execute);
 
-           afterTestabilityCheck(() => {
+           microTask(() => {
              testability.decreasePendingRequestCount();
 
-             afterTestabilityCheck(() => {
+             microTask(() => {
                expect(execute).toHaveBeenCalledWith(true);
                testability.whenStable(execute2);
 
-               afterTestabilityCheck(() => {
+               microTask(() => {
                  expect(execute2).toHaveBeenCalledWith(false);
                  async.done();
                });
@@ -152,7 +154,7 @@ class MockNgZone extends NgZone {
            ngZone.stable();
            testability.whenStable(execute);
 
-           afterTestabilityCheck(() => {
+           microTask(() => {
              expect(execute).toHaveBeenCalled();
              async.done();
            });
@@ -171,11 +173,11 @@ class MockNgZone extends NgZone {
            ngZone.unstable();
            testability.whenStable(execute);
 
-           afterTestabilityCheck(() => {
+           microTask(() => {
              expect(execute).not.toHaveBeenCalled();
              ngZone.stable();
 
-             afterTestabilityCheck(() => {
+             microTask(() => {
                expect(execute).toHaveBeenCalled();
                async.done();
              });
@@ -196,15 +198,15 @@ class MockNgZone extends NgZone {
            testability.increasePendingRequestCount();
            testability.whenStable(execute);
 
-           afterTestabilityCheck(() => {
+           microTask(() => {
              expect(execute).not.toHaveBeenCalled();
              testability.decreasePendingRequestCount();
 
-             afterTestabilityCheck(() => {
+             microTask(() => {
                expect(execute).not.toHaveBeenCalled();
                ngZone.stable();
 
-               afterTestabilityCheck(() => {
+               microTask(() => {
                  expect(execute).toHaveBeenCalled();
                  async.done();
                });
@@ -219,19 +221,19 @@ class MockNgZone extends NgZone {
            testability.increasePendingRequestCount();
            testability.whenStable(execute);
 
-           afterTestabilityCheck(() => {
+           microTask(() => {
              expect(execute).not.toHaveBeenCalled();
              ngZone.stable();
 
-             afterTestabilityCheck(() => {
+             microTask(() => {
                expect(execute).not.toHaveBeenCalled();
                testability.decreasePendingRequestCount();
 
-               afterTestabilityCheck(() => {
+               microTask(() => {
                  expect(execute).not.toHaveBeenCalled();
                  testability.decreasePendingRequestCount();
 
-                 afterTestabilityCheck(() => {
+                 microTask(() => {
                    expect(execute).toHaveBeenCalled();
                    async.done();
                  });
@@ -246,11 +248,11 @@ class MockNgZone extends NgZone {
            ngZone.stable();
            testability.whenStable(execute);
 
-           afterTestabilityCheck(() => {
+           microTask(() => {
              expect(execute).toHaveBeenCalledWith(true);
              testability.whenStable(execute2);
 
-             afterTestabilityCheck(() => {
+             microTask(() => {
                expect(execute2).toHaveBeenCalledWith(false);
                async.done();
              });
@@ -262,14 +264,14 @@ class MockNgZone extends NgZone {
            ngZone.unstable();
            testability.whenStable(execute);
 
-           afterTestabilityCheck(() => {
+           microTask(() => {
              ngZone.stable();
 
-             afterTestabilityCheck(() => {
+             microTask(() => {
                expect(execute).toHaveBeenCalledWith(true);
                testability.whenStable(execute2);
 
-               afterTestabilityCheck(() => {
+               microTask(() => {
                  expect(execute2).toHaveBeenCalledWith(false);
                  async.done();
                });