--- a/webaudio/specification.html	Tue Sep 25 12:56:14 2012 -0700
+++ b/webaudio/specification.html	Wed Sep 26 18:22:36 2012 -0400
@@ -1845,7 +1845,7 @@
 
     <span class="comment">// Playback this in-memory audio asset  </span>
     <span class="comment">// Many sources can share the same buffer  </span>
-    attribute AudioBuffer buffer;
+    attribute AudioBuffer? buffer;
 
     attribute AudioParam playbackRate;
     attribute boolean loop;