diff --git a/transport/hub/udp_server.go b/transport/hub/udp_server.go
index 1fd93092..dc3d46a0 100644
--- a/transport/hub/udp_server.go
+++ b/transport/hub/udp_server.go
@@ -66,6 +66,8 @@ func (this *UDPServer) handleConnection(destString string, inboundRay ray.Inboun
 		callback(source, data)
 	}
 	this.Lock()
+	inboundRay.InboundInput().Release()
+	inboundRay.InboundOutput().Release()
 	delete(this.conns, destString)
 	this.Unlock()
 }