--- a/webaudio/specification.html	Wed May 01 12:36:48 2013 -0700
+++ b/webaudio/specification.html	Wed May 01 22:21:44 2013 -0400
@@ -847,7 +847,7 @@
 
     AudioBuffer createBuffer(unsigned long numberOfChannels, unsigned long length, float sampleRate);
 
-    AudioBuffer createBuffer(ArrayBuffer buffer, boolean mixToMono);
+    AudioBuffer? createBuffer(ArrayBuffer buffer, boolean mixToMono);
 
     void decodeAudioData(ArrayBuffer audioData,
                          DecodeSuccessCallback successCallback,