diff --git a/scripts/fiber/tests-failing.txt b/scripts/fiber/tests-failing.txt
index 8d705c30e8..8db2ea6703 100644
--- a/scripts/fiber/tests-failing.txt
+++ b/scripts/fiber/tests-failing.txt
@@ -18,6 +18,9 @@ src/isomorphic/modern/element/__tests__/ReactJSXElementValidator-test.js
 src/renderers/dom/__tests__/ReactDOMProduction-test.js
 * should throw with an error code in production
 
+src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
+* should reconcile portal children
+
 src/renderers/dom/shared/__tests__/ReactDOM-test.js
 * throws in render() if the mount callback is not a function
 * throws in render() if the update callback is not a function
diff --git a/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js b/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
index fd20ef8a8c..6dd3146541 100644
--- a/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
+++ b/src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
@@ -367,6 +367,82 @@ describe('ReactDOMFiber', () => {
       expect(container.innerHTML).toBe('');
     });
 
+    it('should reconcile portal children', () => {
+      var portalContainer = document.createElement('div');
+
+      ReactDOM.render(
+        <div>
+          {ReactDOM.unstable_createPortal(
+            <div>portal:1</div>,
+            portalContainer
+          )}
+        </div>,
+        container
+      );
+      expect(portalContainer.innerHTML).toBe('<div>portal:1</div>');
+      expect(container.innerHTML).toBe('<div></div>');
+
+      ReactDOM.render(
+        <div>
+          {ReactDOM.unstable_createPortal(
+            <div>portal:2</div>,
+            portalContainer
+          )}
+        </div>,
+        container
+      );
+      expect(portalContainer.innerHTML).toBe('<div>portal:2</div>');
+      expect(container.innerHTML).toBe('<div></div>');
+
+      ReactDOM.render(
+        <div>
+          {ReactDOM.unstable_createPortal(
+            <p>portal:3</p>,
+            portalContainer
+          )}
+        </div>,
+        container
+      );
+      expect(portalContainer.innerHTML).toBe('<p>portal:3</p>');
+      expect(container.innerHTML).toBe('<div></div>');
+
+      ReactDOM.render(
+        <div>
+          {ReactDOM.unstable_createPortal(
+            ['Hi', 'Bye'],
+            portalContainer
+          )}
+        </div>,
+        container
+      );
+      expect(portalContainer.innerHTML).toBe('HiBye');
+      expect(container.innerHTML).toBe('<div></div>');
+
+      ReactDOM.render(
+        <div>
+          {ReactDOM.unstable_createPortal(
+            ['Bye', 'Hi'],
+            portalContainer
+          )}
+        </div>,
+        container
+      );
+      expect(portalContainer.innerHTML).toBe('ByeHi');
+      expect(container.innerHTML).toBe('<div></div>');
+
+      ReactDOM.render(
+        <div>
+          {ReactDOM.unstable_createPortal(
+            null,
+            portalContainer
+          )}
+        </div>,
+        container
+      );
+      expect(portalContainer.innerHTML).toBe('');
+      expect(container.innerHTML).toBe('<div></div>');
+    });
+
     it('should keep track of namespace across portals (simple)', () => {
       assertNamespacesMatch(
         <svg {...expectSVG}>