diff --git a/README.md b/README.md
index 178db5c..f5703e7 100644
--- a/README.md
+++ b/README.md
@@ -29,11 +29,13 @@ func main() {
 	defer task.Close()
     // false for multicast, true for broadcast
 	task.SetBroadcast(false)
-	// set local network ip, default use  is 255.255.255.255
+	// set local network ip, can use  is 255.255.255.255
 	localIP := "192.168.1.2"
-	if localIP != "" {
-		task.SetLocalIP(net.ParseIP(localIP))
+	if localIP == "" {
+		localIP = "255.255.255.255"
 	}
+	task.SetLocalIP(net.ParseIP(localIP))
+	
 	log.Println("SmartConfig run.")
     // smartconfig device num: 1
 	rList := task.ExecuteForResults(1)