diff --git a/src/renderers/dom/client/ReactDOMComponentTree.js b/src/renderers/dom/client/ReactDOMComponentTree.js
index 4d9b8315c853c..8ff3260e8508e 100644
--- a/src/renderers/dom/client/ReactDOMComponentTree.js
+++ b/src/renderers/dom/client/ReactDOMComponentTree.js
@@ -81,7 +81,7 @@ function precacheChildNodes(inst, node) {
     }
     var childInst = children[name];
     var childID = getRenderedHostOrTextFromComponent(childInst)._domID;
-    if (childID == null) {
+    if (childID === 0) {
       // We're currently unmounting this child in ReactMultiChild; skip it.
       continue;
     }
diff --git a/src/renderers/dom/shared/ReactDOMComponent.js b/src/renderers/dom/shared/ReactDOMComponent.js
index ec5ee6339b483..84c59061da007 100644
--- a/src/renderers/dom/shared/ReactDOMComponent.js
+++ b/src/renderers/dom/shared/ReactDOMComponent.js
@@ -483,8 +483,8 @@ function ReactDOMComponent(element) {
   this._previousStyleCopy = null;
   this._hostNode = null;
   this._hostParent = null;
-  this._rootNodeID = null;
-  this._domID = null;
+  this._rootNodeID = 0;
+  this._domID = 0;
   this._hostContainerInfo = null;
   this._wrapperState = null;
   this._topLevelWrapper = null;
@@ -1179,8 +1179,8 @@ ReactDOMComponent.Mixin = {
     this.unmountChildren(safely);
     ReactDOMComponentTree.uncacheNode(this);
     EventPluginHub.deleteAllListeners(this);
-    this._rootNodeID = null;
-    this._domID = null;
+    this._rootNodeID = 0;
+    this._domID = 0;
     this._wrapperState = null;
 
     if (__DEV__) {
diff --git a/src/renderers/dom/shared/ReactDOMEmptyComponent.js b/src/renderers/dom/shared/ReactDOMEmptyComponent.js
index d77ea340582bd..0a7b8c6b2f01f 100644
--- a/src/renderers/dom/shared/ReactDOMEmptyComponent.js
+++ b/src/renderers/dom/shared/ReactDOMEmptyComponent.js
@@ -22,7 +22,7 @@ var ReactDOMEmptyComponent = function(instantiate) {
   this._hostNode = null;
   this._hostParent = null;
   this._hostContainerInfo = null;
-  this._domID = null;
+  this._domID = 0;
 };
 Object.assign(ReactDOMEmptyComponent.prototype, {
   mountComponent: function(
diff --git a/src/renderers/dom/shared/ReactDOMTextComponent.js b/src/renderers/dom/shared/ReactDOMTextComponent.js
index fa589e7886204..24b0027d2600e 100644
--- a/src/renderers/dom/shared/ReactDOMTextComponent.js
+++ b/src/renderers/dom/shared/ReactDOMTextComponent.js
@@ -43,7 +43,7 @@ var ReactDOMTextComponent = function(text) {
   this._hostParent = null;
 
   // Properties
-  this._domID = null;
+  this._domID = 0;
   this._mountIndex = 0;
   this._closingComment = null;
   this._commentNodes = null;
diff --git a/src/renderers/dom/shared/__tests__/ReactDOMComponent-test.js b/src/renderers/dom/shared/__tests__/ReactDOMComponent-test.js
index c2ccb39c2cec4..f87922d9e4f2d 100644
--- a/src/renderers/dom/shared/__tests__/ReactDOMComponent-test.js
+++ b/src/renderers/dom/shared/__tests__/ReactDOMComponent-test.js
@@ -675,7 +675,7 @@ describe('ReactDOMComponent', function() {
 
       var NodeStub = function(initialProps) {
         this._currentElement = {props: initialProps};
-        this._rootNodeID = 'test';
+        this._rootNodeID = 1;
       };
       Object.assign(NodeStub.prototype, ReactDOMComponent.Mixin);
 
@@ -731,7 +731,7 @@ describe('ReactDOMComponent', function() {
 
       var NodeStub = function(initialProps) {
         this._currentElement = {props: initialProps};
-        this._rootNodeID = 'test';
+        this._rootNodeID = 1;
       };
       Object.assign(NodeStub.prototype, ReactDOMComponent.Mixin);
 
diff --git a/src/renderers/native/ReactNativeBaseComponent.js b/src/renderers/native/ReactNativeBaseComponent.js
index 0a0c8435b799d..5d131739fc986 100644
--- a/src/renderers/native/ReactNativeBaseComponent.js
+++ b/src/renderers/native/ReactNativeBaseComponent.js
@@ -59,7 +59,7 @@ ReactNativeBaseComponent.Mixin = {
     ReactNativeComponentTree.uncacheNode(this);
     deleteAllListeners(this);
     this.unmountChildren();
-    this._rootNodeID = null;
+    this._rootNodeID = 0;
   },
 
   /**
diff --git a/src/renderers/native/ReactNativeTextComponent.js b/src/renderers/native/ReactNativeTextComponent.js
index 67a9b865fa421..8e815f9efb20a 100644
--- a/src/renderers/native/ReactNativeTextComponent.js
+++ b/src/renderers/native/ReactNativeTextComponent.js
@@ -22,7 +22,7 @@ var ReactNativeTextComponent = function(text) {
   this._currentElement = text;
   this._stringText = '' + text;
   this._hostParent = null;
-  this._rootNodeID = null;
+  this._rootNodeID = 0;
 };
 
 Object.assign(ReactNativeTextComponent.prototype, {
@@ -73,7 +73,7 @@ Object.assign(ReactNativeTextComponent.prototype, {
     ReactNativeComponentTree.uncacheNode(this);
     this._currentElement = null;
     this._stringText = null;
-    this._rootNodeID = null;
+    this._rootNodeID = 0;
   },
 
 });
diff --git a/src/renderers/native/createReactNativeComponentClass.js b/src/renderers/native/createReactNativeComponentClass.js
index adb0740bcf88e..351a2b5797858 100644
--- a/src/renderers/native/createReactNativeComponentClass.js
+++ b/src/renderers/native/createReactNativeComponentClass.js
@@ -33,7 +33,7 @@ var createReactNativeComponentClass = function(
     this._topLevelWrapper = null;
     this._hostParent = null;
     this._hostContainerInfo = null;
-    this._rootNodeID = null;
+    this._rootNodeID = 0;
     this._renderedChildren = null;
   };
   Constructor.displayName = viewConfig.uiViewClassName;
diff --git a/src/renderers/shared/stack/reconciler/ReactCompositeComponent.js b/src/renderers/shared/stack/reconciler/ReactCompositeComponent.js
index 9b878829aaa66..bce59875a2e08 100644
--- a/src/renderers/shared/stack/reconciler/ReactCompositeComponent.js
+++ b/src/renderers/shared/stack/reconciler/ReactCompositeComponent.js
@@ -150,7 +150,7 @@ var ReactCompositeComponentMixin = {
    */
   construct: function(element) {
     this._currentElement = element;
-    this._rootNodeID = null;
+    this._rootNodeID = 0;
     this._compositeType = null;
     this._instance = null;
     this._hostParent = null;
@@ -609,7 +609,7 @@ var ReactCompositeComponentMixin = {
     // These fields do not really need to be reset since this object is no
     // longer accessible.
     this._context = null;
-    this._rootNodeID = null;
+    this._rootNodeID = 0;
     this._topLevelWrapper = null;
 
     // Delete the reference from the instance to this internal representation