diff --git a/src/renderers/shared/fiber/ReactDebugCurrentFiber.js b/src/renderers/shared/fiber/ReactDebugCurrentFiber.js
index d857e5f2dd..6969cec658 100644
--- a/src/renderers/shared/fiber/ReactDebugCurrentFiber.js
+++ b/src/renderers/shared/fiber/ReactDebugCurrentFiber.js
@@ -14,6 +14,8 @@
 
 import type { Fiber } from 'ReactFiber';
 
+type LifeCyclePhase = 'render' | 'getChildContext';
+
 if (__DEV__) {
   var getComponentName = require('getComponentName');
   var { getStackAddendumByWorkInProgressFiber } = require('ReactComponentTreeHook');
@@ -47,6 +49,8 @@ function getCurrentFiberStackAddendum() : string | null {
 
 var ReactDebugCurrentFiber = {
   current: (null : Fiber | null),
+  phase: (null : LifeCyclePhase | null),
+
   getCurrentFiberOwnerName,
   getCurrentFiberStackAddendum,
 };
diff --git a/src/renderers/shared/fiber/ReactFiberBeginWork.js b/src/renderers/shared/fiber/ReactFiberBeginWork.js
index 7b6d8dc78d..b88be76bf0 100644
--- a/src/renderers/shared/fiber/ReactFiberBeginWork.js
+++ b/src/renderers/shared/fiber/ReactFiberBeginWork.js
@@ -66,7 +66,6 @@ var invariant = require('invariant');
 
 if (__DEV__) {
   var ReactDebugCurrentFiber = require('ReactDebugCurrentFiber');
-  var ReactDebugLifeCycle = require('ReactDebugLifeCycle');
   var warning = require('warning');
   var warnedAboutStatelessRefs = {};
 }
@@ -231,11 +230,9 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
 
     if (__DEV__) {
       ReactCurrentOwner.current = workInProgress;
-      ReactDebugLifeCycle.current = workInProgress;
-      ReactDebugLifeCycle.phase = 'render';
+      ReactDebugCurrentFiber.phase = 'render';
       nextChildren = fn(nextProps, context);
-      ReactDebugLifeCycle.current = null;
-      ReactDebugLifeCycle.phase = null;
+      ReactDebugCurrentFiber.phase = null;
     } else {
       nextChildren = fn(nextProps, context);
     }
@@ -286,11 +283,9 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
     ReactCurrentOwner.current = workInProgress;
     let nextChildren;
     if (__DEV__) {
-      ReactDebugLifeCycle.current = workInProgress;
-      ReactDebugLifeCycle.phase = 'render';
+      ReactDebugCurrentFiber.phase = 'render';
       nextChildren = instance.render();
-      ReactDebugLifeCycle.current = null;
-      ReactDebugLifeCycle.phase = null;
+      ReactDebugCurrentFiber.phase = null;
     } else {
       nextChildren = instance.render();
     }
diff --git a/src/renderers/shared/fiber/ReactFiberContext.js b/src/renderers/shared/fiber/ReactFiberContext.js
index f29b96378a..dbb7a43bd9 100644
--- a/src/renderers/shared/fiber/ReactFiberContext.js
+++ b/src/renderers/shared/fiber/ReactFiberContext.js
@@ -35,7 +35,7 @@ const {
 if (__DEV__) {
   var checkReactTypeSpec = require('checkReactTypeSpec');
   var ReactDebugCurrentFrame = require('ReactDebugCurrentFrame');
-  var ReactDebugLifeCycle = require('ReactDebugLifeCycle');
+  var ReactDebugCurrentFiber = require('ReactDebugCurrentFiber');
   var warnedAboutMissingGetChildContext = {};
 }
 
@@ -171,11 +171,9 @@ function processChildContext(fiber : Fiber, parentContext : Object, isReconcilin
 
   let childContext;
   if (__DEV__) {
-    ReactDebugLifeCycle.current = fiber;
-    ReactDebugLifeCycle.phase = 'getChildContext';
+    ReactDebugCurrentFiber.phase = 'getChildContext';
     childContext = instance.getChildContext();
-    ReactDebugLifeCycle.current = null;
-    ReactDebugLifeCycle.phase = null;
+    ReactDebugCurrentFiber.phase = null;
   } else {
     childContext = instance.getChildContext();
   }
diff --git a/src/renderers/shared/fiber/ReactFiberReconciler.js b/src/renderers/shared/fiber/ReactFiberReconciler.js
index ede6832440..3f910aa1d9 100644
--- a/src/renderers/shared/fiber/ReactFiberReconciler.js
+++ b/src/renderers/shared/fiber/ReactFiberReconciler.js
@@ -32,8 +32,7 @@ var ReactFiberScheduler = require('ReactFiberScheduler');
 if (__DEV__) {
   var warning = require('warning');
   var ReactFiberInstrumentation = require('ReactFiberInstrumentation');
-  var warning = require('warning');
-  var ReactDebugLifeCycle = require('ReactDebugLifeCycle');
+  var ReactDebugCurrentFiber = require('ReactDebugCurrentFiber');
   var { getComponentName } = require('ReactFiberTreeReflection');
 }
 
@@ -148,14 +147,14 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
 
   function scheduleTopLevelUpdate(current : Fiber, element : ReactNodeList, callback : ?Function) {
     if (__DEV__) {
-      if (ReactDebugLifeCycle.current !== null) {
+      if (ReactDebugCurrentFiber.current !== null) {
         warning(
-          ReactDebugLifeCycle.phase !== 'render',
+          ReactDebugCurrentFiber.phase !== 'render',
           'Render methods should be a pure function of props and state; ' +
           'triggering nested component updates from render is not allowed. ' +
           'If necessary, trigger nested updates in componentDidUpdate.\n\n' +
           'Check the render method of %s.',
-          getComponentName(ReactDebugLifeCycle.current)
+          getComponentName(ReactDebugCurrentFiber.current)
         );
       }
     }
diff --git a/src/renderers/shared/fiber/ReactFiberScheduler.js b/src/renderers/shared/fiber/ReactFiberScheduler.js
index 08f08c9fe5..f0b8601da3 100644
--- a/src/renderers/shared/fiber/ReactFiberScheduler.js
+++ b/src/renderers/shared/fiber/ReactFiberScheduler.js
@@ -90,7 +90,6 @@ if (__DEV__) {
   var warning = require('warning');
   var ReactFiberInstrumentation = require('ReactFiberInstrumentation');
   var ReactDebugCurrentFiber = require('ReactDebugCurrentFiber');
-  var ReactDebugLifeCycle = require('ReactDebugLifeCycle');
 
   var warnAboutUpdateOnUnmounted = function(instance : ReactClass<any>) {
     const ctor = instance.constructor;
@@ -105,7 +104,7 @@ if (__DEV__) {
   };
 
   var warnAboutInvalidUpdates = function(instance : ReactClass<any>) {
-    switch (ReactDebugLifeCycle.phase) {
+    switch (ReactDebugCurrentFiber.phase) {
       case 'getChildContext':
         warning(
           false,
@@ -880,8 +879,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(config : HostConfig<T, P,
     ReactCurrentOwner.current = null;
     if (__DEV__) {
       ReactDebugCurrentFiber.current = null;
-      ReactDebugLifeCycle.current = null;
-      ReactDebugLifeCycle.phase = null;
+      ReactDebugCurrentFiber.phase = null;
     }
     // It is no longer valid because this unit of work failed.
     nextUnitOfWork = null;
diff --git a/src/renderers/shared/fiber/isomorphic/ReactDebugLifeCycle.js b/src/renderers/shared/fiber/isomorphic/ReactDebugLifeCycle.js
deleted file mode 100644
index 3e74494e93..0000000000
--- a/src/renderers/shared/fiber/isomorphic/ReactDebugLifeCycle.js
+++ /dev/null
@@ -1,24 +0,0 @@
-/**
- * Copyright 2013-present, 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 ReactDebugLifeCycle
- * @flow
- */
-
-'use strict';
-
-import type { Fiber } from 'ReactFiber';
-
-type LifeCyclePhase = 'render' | 'getChildContext';
-
-const ReactDebugLifeCycle = {
-  current: (null : Fiber | null),
-  phase: (null : LifeCyclePhase | null),
-};
-
-module.exports = ReactDebugLifeCycle;