diff --git a/docs/07-working-with-the-browser.md b/docs/07-working-with-the-browser.md
index c94f45aa..5d7b90f3 100644
--- a/docs/07-working-with-the-browser.md
+++ b/docs/07-working-with-the-browser.md
@@ -126,6 +126,7 @@ In addition to that philosophy, we've also taken the stance that we, as authors
 `es5-sham.js`, also from [kriskowal's es5-shim](https://github.com/kriskowal/es5-shim), provides the following that React needs:
 
 * `Object.create`
+* `Object.freeze`
 
 The unminified build of React needs the following from [paulmillr's console-polyfill](https://github.com/paulmillr/console-polyfill).