diff --git a/jest/jest.d.ts b/jest/jest.d.ts
new file mode 100644
index 0000000000..31fcc07dfc
--- /dev/null
+++ b/jest/jest.d.ts
@@ -0,0 +1,71 @@
+declare var jasmine: any;
+
+declare function afterEach(fn: any): any;
+declare function beforeEach(fn: any): any;
+declare function describe(name: string, fn: any): void;
+declare var it: {
+  (name: string, fn: any): void;
+  only: (name: string, fn: any) => void;
+}
+declare function expect(val: any): Expect;
+declare var jest: Jest;
+declare function pit(name: string, fn: any): void;
+declare function spyOn(obj: any, key: string): any;
+declare function xdescribe(name: string, fn: any): void;
+declare function xit(name: string, fn: any): void;
+
+interface Expect {
+  not: Expect
+  toThrow(message?: string): void
+  toBe(value: any): void
+  toEqual(value: any): void
+  toBeFalsy(): void
+  toBeTruthy(): void
+  toBeNull(): void
+  toBeUndefined(): void
+  toBeDefined(): void
+  toMatch(regexp: RegExp): void
+  toContain(string: string): void
+  toBeCloseTo(number: number, delta: number): void
+  toBeGreaterThan(number: number): void
+  toBeLessThan(number: number): void
+  toBeCalled(): void
+  toBeCalledWith(...arguments): void
+  lastCalledWith(...arguments): void
+}
+
+interface Jest {
+  autoMockOff(): void
+  autoMockOn(): void
+  clearAllTimers(): void
+  dontMock(moduleName: string): void
+  genMockFromModule(moduleObj: Object): Object
+  genMockFunction(): MockFunction
+  genMockFn(): MockFunction
+  mock(moduleName: string): void
+  runAllTicks(): void
+  runAllTimers(): void
+  runOnlyPendingTimers(): void
+  setMock(moduleName: string, moduleExports: Object): void
+}
+
+interface MockFunction {
+  (...arguments): any
+  mock: {
+    calls: Array<Array<any>>
+    instances: Array<Object>
+  }
+  mockClear(): void
+  mockImplementation(fn: Function): MockFunction
+  mockImpl(fn: Function): MockFunction
+  mockReturnThis(): MockFunction
+  mockReturnValue(value: any): MockFunction
+  mockReturnValueOnce(value: any): MockFunction
+}
+
+// Allow importing jasmine-check
+declare module 'jasmine-check' {
+  export function install(global?: any): void;
+}
+declare var check: any;
+declare var gen: any;
diff --git a/jest/preprocessor.js b/jest/preprocessor.js
index 37fdd6ac5f..d52482c816 100644
--- a/jest/preprocessor.js
+++ b/jest/preprocessor.js
@@ -3,12 +3,29 @@
 var ReactTools = require('../main.js');
 
 var coffee = require('coffee-script');
+var ts = require('ts-compiler');
 
 module.exports = {
   process: function(src, path) {
     if (path.match(/\.coffee$/)) {
       return coffee.compile(src, {'bare': true});
     }
+    if (path.match(/\.ts$/) && !path.match(/\.d\.ts$/)) {
+      ts.compile([path], {
+        skipWrite: true,
+        module: 'commonjs'
+      }, function(err, results) {
+        if (err) {
+          throw err;
+        }
+        results.forEach(function(file) {
+          // This is gross, but jest doesn't provide an asynchronous way to
+          // process a module, and ts currently runs syncronously.
+          src = file.text;
+        });
+      });
+      return src;
+    }
     return ReactTools.transform(src, {harmony: true});
   }
 };
diff --git a/package.json b/package.json
index 1d2bb1b806..917c1dc51b 100644
--- a/package.json
+++ b/package.json
@@ -58,6 +58,7 @@
     "populist": "~0.1.6",
     "recast": "^0.9.11",
     "sauce-tunnel": "~1.1.0",
+    "ts-compiler": "^2.0.0",
     "tmp": "~0.0.18",
     "uglify-js": "~2.4.0",
     "uglifyify": "^2.4.0",
@@ -82,7 +83,8 @@
     "setupEnvScriptFile": "jest/environment.js",
     "testFileExtensions": [
       "js",
-      "coffee"
+      "coffee",
+      "ts"
     ],
     "modulePathIgnorePatterns": [
       "/build/",
diff --git a/src/modern/class/__tests__/ReactClassEquivalence-test.js b/src/modern/class/__tests__/ReactClassEquivalence-test.js
index ff48f5373a..cd342ad487 100644
--- a/src/modern/class/__tests__/ReactClassEquivalence-test.js
+++ b/src/modern/class/__tests__/ReactClassEquivalence-test.js
@@ -19,9 +19,14 @@ describe('ReactClassEquivalence', function() {
 
   var es6 = () => require('./ReactES6Class-test.js');
   var coffee = () => require('./ReactCoffeeScriptClass-test.coffee');
+  var ts = () => require('./ReactTypeScriptClass-test.ts');
 
-  it('tests the same thing for es6 classes and coffee script', function() {
+  it('tests the same thing for es6 classes and CoffeeScript', function() {
     expect(coffee).toEqualSpecsIn(es6);
   });
 
+  it('tests the same thing for es6 classes and TypeScript', function() {
+    expect(ts).toEqualSpecsIn(es6);
+  });
+
 });
diff --git a/src/modern/class/__tests__/ReactTypeScriptClass-test.ts b/src/modern/class/__tests__/ReactTypeScriptClass-test.ts
new file mode 100644
index 0000000000..1cbe9e6427
--- /dev/null
+++ b/src/modern/class/__tests__/ReactTypeScriptClass-test.ts
@@ -0,0 +1,491 @@
+/*!
+ * Copyright 2015, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+///<reference path='../../../../jest/jest.d.ts'/>
+///<reference path='./react.d.ts'/>
+
+import React = require('React');
+
+// Before Each
+
+var container;
+var attachedListener = null;
+var renderedName = null;
+
+class Inner extends React.Component {
+  getName() {
+    return this.props.name;
+  }
+  render() {
+    attachedListener = this.props.onClick;
+    renderedName = this.props.name;
+    return React.createElement('div', { className: this.props.name });
+  }
+};
+
+function test(element, expectedTag, expectedClassName) {
+  var instance = React.render(element, container);
+  expect(container.firstChild).not.toBeNull();
+  expect(container.firstChild.tagName).toBe(expectedTag);
+  expect(container.firstChild.className).toBe(expectedClassName);
+  return instance;
+}
+
+// Classes need to be declared at the top level scope, so we declare all the
+// classes that will be used by the tests below, instead of inlining them.
+// TODO: Consider redesigning this using modules so that we can use non-unique
+// names of classes and bundle them with the test code.
+
+// it preserves the name of the class for use in error messages
+// it throws if no render function is defined
+class Empty extends React.Component { }
+
+// it renders a simple stateless component with prop
+class SimpleStateless {
+  props : any;
+  render() {
+    return React.createElement(Inner, {name: this.props.bar});
+  }
+}
+
+// it renders based on state using initial values in this.props
+class InitialState extends React.Component {
+  state = {
+    bar: this.props.initialValue
+  };
+  render() {
+    return React.createElement('span', {className: this.state.bar});
+  }
+}
+
+// it renders based on state using props in the constructor
+class StateBasedOnProps extends React.Component {
+  constructor(props) {
+    super(props);
+    this.state = { bar: props.initialValue };
+  }
+  changeState() {
+    this.setState({ bar: 'bar' });
+  }
+  render() {
+    if (this.state.bar === 'foo') {
+      return React.createElement('div', {className: 'foo'});
+    }
+    return React.createElement('span', {className: this.state.bar});
+  }
+}
+
+// it renders based on context in the constructor
+class StateBasedOnContext extends React.Component {
+  static contextTypes = {
+    tag: React.PropTypes.string,
+    className: React.PropTypes.string
+  }
+  state = {
+    tag: this.context.tag,
+    className: this.context.className
+  }
+  render() {
+    var Tag = this.state.tag;
+    return React.createElement(Tag, {className: this.state.className});
+  }
+}
+
+class ProvideChildContextTypes extends React.Component {
+  static childContextTypes = {
+    tag: React.PropTypes.string,
+    className: React.PropTypes.string
+  }
+  getChildContext() {
+    return { tag: 'span', className: 'foo' };
+  }
+  render() {
+    return React.createElement(StateBasedOnContext);
+  }
+}
+
+// it renders only once when setting state in componentWillMount
+var renderCount = 0;
+class RenderOnce extends React.Component {
+  state = {
+    bar: this.props.initialValue
+  }
+  componentWillMount() {
+    this.setState({ bar: 'bar' });
+  }
+  render() {
+    renderCount++;
+    return React.createElement('span', {className: this.state.bar});
+  }
+}
+
+// it should throw with non-object in the initial state property
+class ArrayState {
+  state = ['an array']
+  render() {
+    return React.createElement('span');
+  }
+}
+class StringState {
+  state = 'a string'
+  render() {
+    return React.createElement('span');
+  }
+}
+class NumberState {
+  state = 1234
+  render() {
+    return React.createElement('span');
+  }
+}
+
+// it should render with null in the initial state property
+class NullState extends React.Component {
+  state = null
+  render() {
+    return React.createElement('span');
+  }
+}
+
+// it setState through an event handler
+class BoundEventHandler extends React.Component {
+  state = {
+    bar: this.props.initialValue
+  }
+  handleClick = () => {
+    this.setState({ bar: 'bar' });
+  }
+  render() {
+    return (
+      React.createElement(Inner, {
+        name: this.state.bar,
+        onClick: this.handleClick
+      })
+    );
+  }
+}
+
+// it should not implicitly bind event handlers
+class UnboundEventHandler extends React.Component {
+  state = {
+    bar: this.props.initialValue
+  }
+  handleClick() {
+    this.setState({ bar: 'bar' });
+  }
+  render() {
+    return React.createElement(
+      Inner, { name: this.state.bar, onClick: this.handleClick }
+    );
+  }
+}
+
+// it renders using forceUpdate even when there is no state
+class ForceUpdateWithNoState extends React.Component {
+  mutativeValue : string = this.props.initialValue
+  handleClick() {
+    this.mutativeValue = 'bar';
+    this.forceUpdate();
+  }
+  render() {
+    return (
+      React.createElement(Inner, {
+        name: this.mutativeValue,
+        onClick: this.handleClick.bind(this)}
+      )
+    );
+  }
+}
+
+// it will call all the normal life cycle methods
+var lifeCycles = [];
+class NormalLifeCycles {
+  props : any
+  state = {}
+  componentWillMount() {
+    lifeCycles.push('will-mount');
+  }
+  componentDidMount() {
+    lifeCycles.push('did-mount');
+  }
+  componentWillReceiveProps(nextProps) {
+    lifeCycles.push('receive-props', nextProps);
+  }
+  shouldComponentUpdate(nextProps, nextState) {
+    lifeCycles.push('should-update', nextProps, nextState);
+    return true;
+  }
+  componentWillUpdate(nextProps, nextState) {
+    lifeCycles.push('will-update', nextProps, nextState);
+  }
+  componentDidUpdate(prevProps, prevState) {
+    lifeCycles.push('did-update', prevProps, prevState);
+  }
+  componentWillUnmount() {
+    lifeCycles.push('will-unmount');
+  }
+  render() {
+    return React.createElement('span', {className: this.props.value});
+  }
+}
+
+// warns when classic properties are defined on the instance,
+// but does not invoke them.
+var getInitialStateWasCalled = false;
+class ClassicProperties extends React.Component {
+  contextTypes = {};
+  propTypes = {};
+  getInitialState() {
+    getInitialStateWasCalled = true;
+    return {};
+  }
+  render() {
+    return React.createElement('span', {className: 'foo'});
+  }
+}
+
+// it should warn when mispelling shouldComponentUpdate
+class NamedComponent {
+  componentShouldUpdate() {
+    return false;
+  }
+  render() {
+    return React.createElement('span', {className: 'foo'});
+  }
+}
+
+// it supports this.context passed via getChildContext
+class ReadContext extends React.Component {
+  static contextTypes = { bar: React.PropTypes.string };
+  render() {
+    return React.createElement('div', { className: this.context.bar });
+  }
+}
+class ProvideContext {
+  static childContextTypes = { bar: React.PropTypes.string };
+  getChildContext() {
+    return { bar: 'bar-through-context' };
+  }
+  render() {
+    return React.createElement(ReadContext);
+  }
+}
+
+// it supports classic refs
+class ClassicRefs {
+  render() {
+    return React.createElement(Inner, {name: 'foo', ref: 'inner'});
+  }
+}
+
+// Describe the actual test cases.
+
+describe('ReactTypeScriptClass', function() {
+
+  beforeEach(function() {
+    container = document.createElement('div');
+    attachedListener = null;
+    renderedName = null;
+  });
+
+  it('preserves the name of the class for use in error messages', function() {
+    expect(Empty.name).toBe('Empty');
+  });
+
+  it('throws if no render function is defined', function() {
+    expect(() => React.render(React.createElement(Empty), container)).toThrow();
+  });
+
+  it('renders a simple stateless component with prop', function() {
+    test(React.createElement(SimpleStateless, {bar: 'foo'}), 'DIV', 'foo');
+    test(React.createElement(SimpleStateless, {bar: 'bar'}), 'DIV', 'bar');
+  });
+
+  it('renders based on state using initial values in this.props', function() {
+    test(
+      React.createElement(InitialState, {initialValue: 'foo'}),
+      'SPAN',
+      'foo'
+    );
+  });
+
+  it('renders based on state using props in the constructor', function() {
+    var instance = test(
+      React.createElement(StateBasedOnProps, {initialValue: 'foo'}),
+      'DIV',
+      'foo'
+    );
+    instance.changeState();
+    test(React.createElement(StateBasedOnProps), 'SPAN', 'bar');
+  });
+
+  it('renders based on context in the constructor', function() {
+    test(React.createElement(ProvideChildContextTypes), 'SPAN', 'foo');
+  });
+
+  it('renders only once when setting state in componentWillMount', function() {
+    renderCount = 0;
+    test(React.createElement(RenderOnce, {initialValue: 'foo'}), 'SPAN', 'bar');
+    expect(renderCount).toBe(1);
+  });
+
+  it('should throw with non-object in the initial state property', function() {
+    expect(() => test(React.createElement(ArrayState), 'span', ''))
+    .toThrow(
+      'Invariant Violation: ArrayState.state: ' +
+      'must be set to an object or null'
+    );
+    expect(() => test(React.createElement(StringState), 'span', ''))
+    .toThrow(
+      'Invariant Violation: StringState.state: ' +
+      'must be set to an object or null'
+    );
+    expect(() => test(React.createElement(NumberState), 'span', ''))
+    .toThrow(
+      'Invariant Violation: NumberState.state: ' +
+      'must be set to an object or null'
+    );
+  });
+
+  it('should render with null in the initial state property', function() {
+    test(React.createElement(NullState), 'SPAN', '');
+  });
+
+  it('setState through an event handler', function() {
+    test(
+      React.createElement(BoundEventHandler, {initialValue: 'foo'}),
+      'DIV',
+      'foo'
+    );
+    attachedListener();
+    expect(renderedName).toBe('bar');
+  });
+
+  it('should not implicitly bind event handlers', function() {
+    test(
+      React.createElement(UnboundEventHandler, {initialValue: 'foo'}),
+      'DIV',
+      'foo'
+    );
+    expect(attachedListener).toThrow();
+  });
+
+  it('renders using forceUpdate even when there is no state', function() {
+    test(
+      React.createElement(ForceUpdateWithNoState, {initialValue: 'foo'}),
+      'DIV',
+      'foo'
+    );
+    attachedListener();
+    expect(renderedName).toBe('bar');
+  });
+
+  it('will call all the normal life cycle methods', function() {
+    lifeCycles = [];
+    test(React.createElement(NormalLifeCycles, {value: 'foo'}), 'SPAN', 'foo');
+    expect(lifeCycles).toEqual([
+      'will-mount',
+      'did-mount'
+    ]);
+    lifeCycles = []; // reset
+    test(React.createElement(NormalLifeCycles, {value: 'bar'}), 'SPAN', 'bar');
+    expect(lifeCycles).toEqual([
+      'receive-props', { value: 'bar' },
+      'should-update', { value: 'bar' }, {},
+      'will-update', { value: 'bar' }, {},
+      'did-update', { value: 'foo' }, {}
+    ]);
+    lifeCycles = []; // reset
+    React.unmountComponentAtNode(container);
+    expect(lifeCycles).toEqual([
+      'will-unmount'
+    ]);
+  });
+
+  it('warns when classic properties are defined on the instance, ' +
+     'but does not invoke them.', function() {
+    var warn = jest.genMockFn();
+    console.warn = warn;
+    getInitialStateWasCalled = false;
+    test(React.createElement(ClassicProperties), 'SPAN', 'foo');
+    expect(getInitialStateWasCalled).toBe(false);
+    expect(warn.mock.calls.length).toBe(3);
+    expect(warn.mock.calls[0][0]).toContain(
+      'getInitialState was defined on ClassicProperties, ' +
+      'a plain JavaScript class.'
+    );
+    expect(warn.mock.calls[1][0]).toContain(
+      'propTypes was defined as an instance property on ClassicProperties.'
+    );
+    expect(warn.mock.calls[2][0]).toContain(
+      'contextTypes was defined as an instance property on ClassicProperties.'
+    );
+  });
+
+  it('should warn when mispelling shouldComponentUpdate', function() {
+    var warn = jest.genMockFn();
+    console.warn = warn;
+
+    test(React.createElement(NamedComponent), 'SPAN', 'foo');
+
+    expect(warn.mock.calls.length).toBe(1);
+    expect(warn.mock.calls[0][0]).toBe(
+      'Warning: ' +
+      'NamedComponent has a method called componentShouldUpdate(). Did you ' +
+      'mean shouldComponentUpdate()? The name is phrased as a question ' +
+      'because the function is expected to return a value.'
+    );
+  });
+
+  it('should throw AND warn when trying to access classic APIs', function() {
+    var warn = jest.genMockFn();
+    console.warn = warn;
+    var instance = test(
+      React.createElement(Inner, {name: 'foo'}),
+      'DIV','foo'
+    );
+    expect(() => instance.getDOMNode()).toThrow();
+    expect(() => instance.replaceState({})).toThrow();
+    expect(() => instance.isMounted()).toThrow();
+    expect(() => instance.setProps({ name: 'bar' })).toThrow();
+    expect(warn.mock.calls.length).toBe(4);
+    expect(warn.mock.calls[0][0]).toContain(
+      'getDOMNode(...) is deprecated in plain JavaScript React classes'
+    );
+    expect(warn.mock.calls[1][0]).toContain(
+      'replaceState(...) is deprecated in plain JavaScript React classes'
+    );
+    expect(warn.mock.calls[2][0]).toContain(
+      'isMounted(...) is deprecated in plain JavaScript React classes'
+    );
+    expect(warn.mock.calls[3][0]).toContain(
+      'setProps(...) is deprecated in plain JavaScript React classes'
+    );
+  });
+
+  it('supports this.context passed via getChildContext', function() {
+    test(React.createElement(ProvideContext), 'DIV', 'bar-through-context');
+  });
+
+  it('supports classic refs', function() {
+    var instance = test(React.createElement(ClassicRefs), 'DIV', 'foo');
+    expect(instance.refs.inner.getName()).toBe('foo');
+  });
+
+  it('supports drilling through to the DOM using findDOMNode', function() {
+    var instance = test(
+      React.createElement(Inner, {name: 'foo'}),
+      'DIV',
+      'foo'
+    );
+    var node = React.findDOMNode(instance);
+    expect(node).toBe(container.firstChild);
+  });
+
+});
diff --git a/src/modern/class/__tests__/react.d.ts b/src/modern/class/__tests__/react.d.ts
new file mode 100644
index 0000000000..ff317606ae
--- /dev/null
+++ b/src/modern/class/__tests__/react.d.ts
@@ -0,0 +1,32 @@
+/*!
+ * Copyright 2015, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+/**
+ * TypeScript Definition File for React.
+ *
+ * Full type definitions are not yet officially supported. These are mostly
+ * just helpers for the unit test.
+ */
+
+declare module 'React' {
+  export class Component {
+    props: any;
+    state: any;
+    context: any;
+    static name: string;
+    constructor(props?, context?);
+    setState(partial : any, callback ?: any) : void;
+    forceUpdate(callback ?: any) : void;
+  }
+  export var PropTypes : any;
+  export function createElement(tag : any, props ?: any, ...children : any[]) : any
+  export function render(element : any, container : any) : any
+  export function unmountComponentAtNode(container : any) : void
+  export function findDOMNode(instance : any) : any
+}