diff --git a/src/classic/class/ReactClass.js b/src/classic/class/ReactClass.js
index 6eeb115203..21e0782763 100644
--- a/src/classic/class/ReactClass.js
+++ b/src/classic/class/ReactClass.js
@@ -485,13 +485,11 @@ function mixSpecIntoComponent(Constructor, spec) {
       var isReactClassMethod =
         ReactClassInterface.hasOwnProperty(name);
       var isAlreadyDefined = proto.hasOwnProperty(name);
-      var markedDontBind = property && property.__reactDontBind;
       var isFunction = typeof property === 'function';
       var shouldAutoBind =
         isFunction &&
         !isReactClassMethod &&
-        !isAlreadyDefined &&
-        !markedDontBind;
+        !isAlreadyDefined;
 
       if (shouldAutoBind) {
         if (!proto.__reactAutoBindMap) {
diff --git a/src/classic/class/ReactDoNotBindDeprecated.js b/src/classic/class/ReactDoNotBindDeprecated.js
deleted file mode 100644
index d43111b890..0000000000
--- a/src/classic/class/ReactDoNotBindDeprecated.js
+++ /dev/null
@@ -1,43 +0,0 @@
-/**
- * Copyright 2013-2015, 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.
- *
- * @providesModule ReactDoNotBindDeprecated
- */
-
-'use strict';
-
-var ReactDoNotBindDeprecated = {
-  /**
-   * Marks the method for not being automatically bound on component mounting. A
-   * couple of reasons you might want to use this:
-   *
-   * - Automatically supporting the previous behavior in components that were
-   *   built with previous versions of React.
-   * - Tuning performance, by avoiding binding on initial render for methods
-   *   that are always invoked while being preceded by `this.`. Such binds are
-   *   unnecessary.
-   *
-   *   React.createClass({
-   *     handleClick: ReactDoNotBindDeprecated.doNotBind(function() {
-   *       alert(this.setState); // undefined!
-   *     }),
-   *     render: function() {
-   *       return <a onClick={this.handleClick}>Jump</a>;
-   *     }
-   *   });
-   *
-   * @param {function} method Method to avoid automatically binding.
-   * @public
-   */
-  doNotBind: function(method) {
-    method.__reactDontBind = true;   // Mutating
-    return method;
-  }
-};
-
-module.exports = ReactDoNotBindDeprecated;
diff --git a/src/classic/class/__tests__/ReactBind-test.js b/src/classic/class/__tests__/ReactBind-test.js
index 856131a978..78caa70c64 100644
--- a/src/classic/class/__tests__/ReactBind-test.js
+++ b/src/classic/class/__tests__/ReactBind-test.js
@@ -13,7 +13,6 @@
 
 var mocks = require('mocks');
 var React = require('React');
-var ReactDoNotBindDeprecated = require('ReactDoNotBindDeprecated');
 var ReactTestUtils = require('ReactTestUtils');
 var reactComponentExpect = require('reactComponentExpect');
 
@@ -30,8 +29,8 @@ describe('autobinding', function() {
       getInitialState: function() {
         return {something: 'hi'};
       },
-      onMouseEnter: ReactDoNotBindDeprecated.doNotBind(mouseDidEnter),
-      onMouseLeave: ReactDoNotBindDeprecated.doNotBind(mouseDidLeave),
+      onMouseEnter: mouseDidEnter,
+      onMouseLeave: mouseDidLeave,
       onClick: mouseDidClick,
 
       // auto binding only occurs on top level functions in class defs.
@@ -44,7 +43,7 @@ describe('autobinding', function() {
       render: function() {
         return (
           <div
-            onMouseOver={this.onMouseEnter.bind(this)}
+            onMouseOver={this.onMouseEnter}
             onMouseOut={this.onMouseLeave}
             onClick={this.onClick}
           />
@@ -69,8 +68,6 @@ describe('autobinding', function() {
       badIdea();
     }).toThrow();
 
-    expect(mountedInstance1.onMouseEnter).toBe(mountedInstance2.onMouseEnter);
-    expect(mountedInstance1.onMouseLeave).toBe(mountedInstance2.onMouseLeave);
     expect(mountedInstance1.onClick).not.toBe(mountedInstance2.onClick);
 
     ReactTestUtils.Simulate.click(rendered1);
@@ -91,11 +88,11 @@ describe('autobinding', function() {
 
     ReactTestUtils.Simulate.mouseOut(rendered1);
     expect(mouseDidLeave.mock.instances.length).toBe(1);
-    expect(mouseDidLeave.mock.instances[0]).toBe(global);
+    expect(mouseDidLeave.mock.instances[0]).toBe(mountedInstance1);
 
     ReactTestUtils.Simulate.mouseOut(rendered2);
     expect(mouseDidLeave.mock.instances.length).toBe(2);
-    expect(mouseDidLeave.mock.instances[1]).toBe(global);
+    expect(mouseDidLeave.mock.instances[1]).toBe(mountedInstance2);
   });
 
   it('works with mixins', function() {
diff --git a/src/core/__tests__/ReactCompositeComponent-test.js b/src/core/__tests__/ReactCompositeComponent-test.js
index 669f2c6c2c..09bae039cc 100644
--- a/src/core/__tests__/ReactCompositeComponent-test.js
+++ b/src/core/__tests__/ReactCompositeComponent-test.js
@@ -15,7 +15,6 @@ var ChildUpdates;
 var MorphingComponent;
 var React;
 var ReactCurrentOwner;
-var ReactDoNotBindDeprecated;
 var ReactMount;
 var ReactPropTypes;
 var ReactServerRendering;
@@ -33,7 +32,6 @@ describe('ReactCompositeComponent', function() {
     reactComponentExpect = require('reactComponentExpect');
     React = require('React');
     ReactCurrentOwner = require('ReactCurrentOwner');
-    ReactDoNotBindDeprecated = require('ReactDoNotBindDeprecated');
     ReactPropTypes = require('ReactPropTypes');
     ReactTestUtils = require('ReactTestUtils');
     ReactMount = require('ReactMount');
@@ -170,9 +168,6 @@ describe('ReactCompositeComponent', function() {
       methodAutoBound: function() {
         return this;
       },
-      methodExplicitlyNotBound: ReactDoNotBindDeprecated.doNotBind(function() {
-        return this;
-      }),
       render: function() {
         return <div></div>;
       }
@@ -189,9 +184,6 @@ describe('ReactCompositeComponent', function() {
     expect(function() {
       mountedInstance.methodAutoBound();
     }).not.toThrow();
-    expect(function() {
-      mountedInstance.methodExplicitlyNotBound();
-    }).not.toThrow();
 
     expect(console.error.argsForCall.length).toBe(1);
     var explicitlyBound = mountedInstance.methodToBeExplicitlyBound.bind(
@@ -199,17 +191,13 @@ describe('ReactCompositeComponent', function() {
     );
     expect(console.error.argsForCall.length).toBe(2);
     var autoBound = mountedInstance.methodAutoBound;
-    var explicitlyNotBound = mountedInstance.methodExplicitlyNotBound;
 
     var context = {};
     expect(explicitlyBound.call(context)).toBe(mountedInstance);
     expect(autoBound.call(context)).toBe(mountedInstance);
-    expect(explicitlyNotBound.call(context)).toBe(context);
 
     expect(explicitlyBound.call(mountedInstance)).toBe(mountedInstance);
     expect(autoBound.call(mountedInstance)).toBe(mountedInstance);
-    // This one is the weird one
-    expect(explicitlyNotBound.call(mountedInstance)).toBe(mountedInstance);
 
   });