diff --git a/os2-udp.rkt b/os2-udp.rkt
index 21b1552..ff337d0 100644
--- a/os2-udp.rkt
+++ b/os2-udp.rkt
@@ -72,10 +72,16 @@
 		     [(topic _ (handle-mapping local-addr socket) _)
 		      (transition (set-remove active-handles local-addr))]))))
 
+(define (bind-socket! s local-addr)
+  (cond
+   [(udp-listener? local-addr) (udp-bind! s #f (udp-listener-port local-addr))]
+   [(udp-handle? local-addr) (udp-bind! s #f 0)]
+   [else (void)]))
+
 ;; UdpAddress -> BootK
 (define ((udp-socket-manager local-addr) self-pid)
   (define s (udp-open-socket #f #f))
-  (when (udp-listener? local-addr) (udp-bind! s #f (udp-listener-port local-addr)))
+  (bind-socket! s local-addr)
   (define buffer (make-bytes 65536)) ;; TODO: buffer size control
   (transition 'socket-is-open
     ;; Offers a handle-mapping on the local network so that the