diff --git a/src/isomorphic/ReactDebugTool.js b/src/isomorphic/ReactDebugTool.js
index 9fd6aa6e2d..92fbcc0bce 100644
--- a/src/isomorphic/ReactDebugTool.js
+++ b/src/isomorphic/ReactDebugTool.js
@@ -73,17 +73,17 @@ var ReactDebugTool = {
   onSetText(debugID, text) {
     emitEvent('onSetText', debugID, text);
   },
-  onMountRootComponent(internalInstance) {
-    emitEvent('onMountRootComponent', internalInstance);
+  onMountRootComponent(debugID) {
+    emitEvent('onMountRootComponent', debugID);
   },
-  onMountComponent(internalInstance) {
-    emitEvent('onMountComponent', internalInstance);
+  onMountComponent(debugID) {
+    emitEvent('onMountComponent', debugID);
   },
-  onUpdateComponent(internalInstance) {
-    emitEvent('onUpdateComponent', internalInstance);
+  onUpdateComponent(debugID) {
+    emitEvent('onUpdateComponent', debugID);
   },
-  onUnmountComponent(internalInstance) {
-    emitEvent('onUnmountComponent', internalInstance);
+  onUnmountComponent(debugID) {
+    emitEvent('onUnmountComponent', debugID);
   },
 };
 
diff --git a/src/isomorphic/__tests__/ReactDebugTool-test.js b/src/isomorphic/__tests__/ReactDebugTool-test.js
index 85d6d64b02..b664ecfd2a 100644
--- a/src/isomorphic/__tests__/ReactDebugTool-test.js
+++ b/src/isomorphic/__tests__/ReactDebugTool-test.js
@@ -22,22 +22,22 @@ describe('ReactDebugTool', () => {
   function createDevtool() {
     var tree = {};
 
-    function updateTree(debugID, update) {
-      if (!tree[debugID]) {
-        tree[debugID] = {};
+    function updateTree(id, update) {
+      if (!tree[id]) {
+        tree[id] = {};
       }
-      update(tree[debugID]);
+      update(tree[id]);
     }
 
-    function getTree(debugID, includeOwner) {
-      var item = tree[debugID];
+    function getTree(id, includeOwner) {
+      var item = tree[id];
       var result = {
         isComposite: item.isComposite,
         displayName: item.displayName,
       };
-      if (item.childDebugIDs) {
-        result.children = item.childDebugIDs.map(childDebugID =>
-          getTree(childDebugID, includeOwner)
+      if (item.childIDs) {
+        result.children = item.childIDs.map(childID =>
+          getTree(childID, includeOwner)
         );
       }
       if (item.text != null) {
@@ -49,29 +49,57 @@ describe('ReactDebugTool', () => {
       return result;
     }
 
+    function purgeTree(id) {
+      var item = tree[id];
+      if (!item) {
+        return;
+      }
+
+      var {childIDs} = item;
+      delete tree[id];
+
+      if (childIDs) {
+        childIDs.forEach(purgeTree);
+      }
+    }
+
     return {
-      onSetIsComposite(debugID, isComposite) {
-        updateTree(debugID, item => item.isComposite = isComposite);
+      onSetIsComposite(id, isComposite) {
+        updateTree(id, item => item.isComposite = isComposite);
       },
-      onSetDisplayName(debugID, displayName) {
-        updateTree(debugID, item => item.displayName = displayName);
+
+      onSetDisplayName(id, displayName) {
+        updateTree(id, item => item.displayName = displayName);
       },
-      onSetChildren(debugID, childDebugIDs) {
-        childDebugIDs.forEach(childDebugID => {
-          var childItem = tree[childDebugID];
+
+      onSetChildren(id, childIDs) {
+        childIDs.forEach(childID => {
+          var childItem = tree[childID];
           expect(childItem).toBeDefined();
           expect(childItem.isComposite).toBeDefined();
           expect(childItem.displayName).toBeDefined();
-          expect(childItem.childDebugIDs || childItem.text).toBeDefined();
+          expect(childItem.childIDs || childItem.text).toBeDefined();
         });
-        updateTree(debugID, item => item.childDebugIDs = childDebugIDs);
+
+        updateTree(id, item => item.childIDs = childIDs);
       },
-      onSetOwner(debugID, ownerDebugID) {
-        updateTree(debugID, item => item.ownerDebugID = ownerDebugID);
+
+      onSetOwner(id, ownerDebugID) {
+        updateTree(id, item => item.ownerDebugID = ownerDebugID);
       },
-      onSetText(debugID, text) {
-        updateTree(debugID, item => item.text = text);
+
+      onSetText(id, text) {
+        updateTree(id, item => item.text = text);
       },
+
+      onUnmountComponent(id) {
+        purgeTree(id);
+      },
+
+      getRegisteredDebugIDs() {
+        return Object.keys(tree);
+      },
+
       getTree(rootDebugID, includeOwner) {
         return getTree(rootDebugID, includeOwner);
       },
@@ -119,6 +147,9 @@ describe('ReactDebugTool', () => {
       );
       expect(actualTree).toEqual(expectedTree);
     });
+
+    ReactDOM.unmountComponentAtNode(node);
+    expect(devtool.getRegisteredDebugIDs()).toEqual([]);
   }
 
   describe('mount', () => {
diff --git a/src/renderers/dom/client/ReactMount.js b/src/renderers/dom/client/ReactMount.js
index 7f6f8cac6f..8f62d5b930 100644
--- a/src/renderers/dom/client/ReactMount.js
+++ b/src/renderers/dom/client/ReactMount.js
@@ -349,7 +349,7 @@ var ReactMount = {
     instancesByReactRootID[wrapperID] = componentInstance;
 
     if (__DEV__) {
-      ReactInstrumentation.debugTool.onMountRootComponent(componentInstance);
+      ReactInstrumentation.debugTool.onMountRootComponent(componentInstance._debugID);
     }
 
     return componentInstance;
diff --git a/src/renderers/dom/shared/ReactDOMComponent.js b/src/renderers/dom/shared/ReactDOMComponent.js
index 50db5019d4..f6d4823a1c 100644
--- a/src/renderers/dom/shared/ReactDOMComponent.js
+++ b/src/renderers/dom/shared/ReactDOMComponent.js
@@ -453,6 +453,7 @@ function ReactDOMComponent(element) {
   this._flags = 0;
   if (__DEV__) {
     this._ancestorInfo = null;
+    this._contentDebugID = null;
   }
 }
 
@@ -758,11 +759,11 @@ ReactDOMComponent.Mixin = {
       if (contentToUse != null) {
         // TODO: Validate that text is allowed as a child of this node
         if (__DEV__) {
-          var inlinedTextDebugID = this._debugID + '#text';
-          ReactInstrumentation.debugTool.onSetIsComposite(inlinedTextDebugID, false);
-          ReactInstrumentation.debugTool.onSetDisplayName(inlinedTextDebugID, '#text');
-          ReactInstrumentation.debugTool.onSetText(inlinedTextDebugID, '' + contentToUse);
-          ReactInstrumentation.debugTool.onSetChildren(this._debugID, [inlinedTextDebugID]);
+          this._contentDebugID = this._debugID + '#text';
+          ReactInstrumentation.debugTool.onSetIsComposite(this._contentDebugID, false);
+          ReactInstrumentation.debugTool.onSetDisplayName(this._contentDebugID, '#text');
+          ReactInstrumentation.debugTool.onSetText(this._contentDebugID, '' + contentToUse);
+          ReactInstrumentation.debugTool.onSetChildren(this._debugID, [this._contentDebugID]);
         }
         DOMLazyTree.queueText(lazyTree, contentToUse);
       } else if (childrenToUse != null) {
@@ -1020,11 +1021,11 @@ ReactDOMComponent.Mixin = {
       if (lastContent !== nextContent) {
         this.updateTextContent('' + nextContent);
         if (__DEV__) {
-          var inlinedTextDebugID = this._debugID + '#text';
-          ReactInstrumentation.debugTool.onSetIsComposite(inlinedTextDebugID, false);
-          ReactInstrumentation.debugTool.onSetDisplayName(inlinedTextDebugID, '#text');
-          ReactInstrumentation.debugTool.onSetText(inlinedTextDebugID, '' + nextContent);
-          ReactInstrumentation.debugTool.onSetChildren(this._debugID, [inlinedTextDebugID]);
+          this._contentDebugID = this._debugID + '#text';
+          ReactInstrumentation.debugTool.onSetIsComposite(this._contentDebugID, false);
+          ReactInstrumentation.debugTool.onSetDisplayName(this._contentDebugID, '#text');
+          ReactInstrumentation.debugTool.onSetText(this._contentDebugID, '' + nextContent);
+          ReactInstrumentation.debugTool.onSetChildren(this._debugID, [this._contentDebugID]);
         }
       }
     } else if (nextHtml != null) {
@@ -1035,6 +1036,13 @@ ReactDOMComponent.Mixin = {
         ReactInstrumentation.debugTool.onSetChildren(this._debugID, []);
       }
     } else if (nextChildren != null) {
+      if (__DEV__) {
+        if (this._contentDebugID) {
+          ReactInstrumentation.debugTool.onUnmountComponent(this._contentDebugID);
+          this._contentDebugID = null;
+        }
+      }
+
       this.updateChildren(nextChildren, transaction, context);
     }
   },
@@ -1096,6 +1104,11 @@ ReactDOMComponent.Mixin = {
     this._rootNodeID = null;
     this._domID = null;
     this._wrapperState = null;
+
+    if (this._contentDebugID) {
+      ReactInstrumentation.debugTool.onUnmountComponent(this._contentDebugID);
+      this._contentDebugID = null;
+    }
   },
 
   getPublicInstance: function() {
diff --git a/src/renderers/shared/reconciler/ReactReconciler.js b/src/renderers/shared/reconciler/ReactReconciler.js
index ae7806e4fc..f6741a84ed 100644
--- a/src/renderers/shared/reconciler/ReactReconciler.js
+++ b/src/renderers/shared/reconciler/ReactReconciler.js
@@ -53,7 +53,7 @@ var ReactReconciler = {
       transaction.getReactMountReady().enqueue(attachRefs, internalInstance);
     }
     if (__DEV__) {
-      ReactInstrumentation.debugTool.onMountComponent(internalInstance);
+      ReactInstrumentation.debugTool.onMountComponent(internalInstance._debugID);
     }
     return markup;
   },
@@ -76,7 +76,7 @@ var ReactReconciler = {
     ReactRef.detachRefs(internalInstance, internalInstance._currentElement);
     internalInstance.unmountComponent(safely);
     if (__DEV__) {
-      ReactInstrumentation.debugTool.onUnmountComponent(internalInstance);
+      ReactInstrumentation.debugTool.onUnmountComponent(internalInstance._debugID);
     }
   },
 
@@ -128,7 +128,7 @@ var ReactReconciler = {
     }
 
     if (__DEV__) {
-      ReactInstrumentation.debugTool.onUpdateComponent(internalInstance);
+      ReactInstrumentation.debugTool.onUpdateComponent(internalInstance._debugID);
     }
   },
 
@@ -145,7 +145,7 @@ var ReactReconciler = {
   ) {
     internalInstance.performUpdateIfNecessary(transaction);
     if (__DEV__) {
-      ReactInstrumentation.debugTool.onUpdateComponent(internalInstance);
+      ReactInstrumentation.debugTool.onUpdateComponent(internalInstance._debugID);
     }
   },