client.go | 7 ++++++-

diff --git a/client.go b/client.go
index 66667e2be1ef01ff49d09a31b1f1d55225555e02..406f5dde6820694850ae6272bf8c154fa27cf9e1 100644
--- a/client.go
+++ b/client.go
@@ -964,7 +964,12 @@ 			addr, _ := c.Socket.RemoteAddr().(*net.TCPAddr)
 			_, err = me.dHT.Ping(&net.UDPAddr{
 				IP:   addr.IP,
 				Zone: addr.Zone,
-				Port: int(msg.Port),
+				Port: func() int {
+					if msg.Port == 0 {
+						return addr.Port
+					}
+					return int(msg.Port)
+				}(),
 			})
 		default:
 			err = fmt.Errorf("received unknown message type: %#v", msg.Type)