diff --git a/rtl8720dn/netdriver.go b/rtl8720dn/netdriver.go
index 73e6cc4..629b491 100644
--- a/rtl8720dn/netdriver.go
+++ b/rtl8720dn/netdriver.go
@@ -71,10 +71,13 @@ func (d *Driver) ConnectTCPSocket(addr, port string) error {
 	name[6] = byte(ipaddr[2])
 	name[7] = byte(ipaddr[3])
 
-	_, err = d.Rpc_lwip_connect(socket, name, uint32(len(name)))
+	result, err := d.Rpc_lwip_connect(socket, name, uint32(len(name)))
 	if err != nil {
 		return err
 	}
+	if result == -1 {
+		return fmt.Errorf("failed to connect to %d.%d.%d.%d port %s", addr[0], addr[1], addr[2], addr[3], port)
+	}
 
 	readset := []byte{}
 	writeset := []byte{0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}