diff --git a/src/browser/ui/React.js b/src/browser/ui/React.js
index 3e8a5159b9..f1175469b3 100644
--- a/src/browser/ui/React.js
+++ b/src/browser/ui/React.js
@@ -65,6 +65,10 @@ var React = {
   createClass: ReactClass.createClass,
   createElement: createElement,
   createFactory: createFactory,
+  createMixin: function(mixin) {
+    // Currently a noop. Will be used to validate and trace mixins.
+    return mixin;
+  },
   constructAndRenderComponent: ReactMount.constructAndRenderComponent,
   constructAndRenderComponentByID: ReactMount.constructAndRenderComponentByID,
   findDOMNode: findDOMNode,