diff --git a/_config.yml b/_config.yml
index 75ca27e2..457559ad 100644
--- a/_config.yml
+++ b/_config.yml
@@ -34,4 +34,4 @@ sass:
   sass_dir: _css
 gems:
 - jekyll-redirect-from
-react_version: 0.11.1
+react_version: 0.12.0-alpha
diff --git a/docs/ref-05-events.md b/docs/ref-05-events.md
index f331d010..7ce50f6a 100644
--- a/docs/ref-05-events.md
+++ b/docs/ref-05-events.md
@@ -10,6 +10,10 @@ next: dom-differences.html
 
 Your event handlers will be passed instances of `SyntheticEvent`, a cross-browser wrapper around the browser's native event. It has the same interface as the browser's native event, including `stopPropagation()` and `preventDefault()`, except the events work identically across all browsers.
 
+> Note:
+>
+> Prior to v0.12, event handlers could return `false` to stop propagation. This behavior is no longer supported; instead, `stopPropagation()` and `preventDefault()` should be triggered manually.
+
 If you find that you need the underlying browser event for some reason, simply use the `nativeEvent` attribute to get it. Every `SyntheticEvent` object has the following attributes:
 
 ```javascript
@@ -111,7 +115,7 @@ onDragOver onDragStart onDrop onMouseDown onMouseEnter onMouseLeave
 onMouseMove onMouseOut onMouseOver onMouseUp
 ```
 
-Properties: 
+Properties:
 
 ```javascript
 boolean altKey