--- AnyEvent/lib/AnyEvent.pm	2009/08/05 20:50:27	1.271
+++ AnyEvent/lib/AnyEvent.pm	2009/08/06 13:31:01	1.272
@@ -1686,8 +1686,8 @@
    AnyEvent->idle (cb => $_[0]);
 }
 
-sub cv() {
-   AnyEvent->condvar
+sub cv(;&) {
+   AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
 }
 
 sub now() {