diff --git a/net/lwip/src/arch/sys_arch_init.c b/net/lwip/src/arch/sys_arch_init.c
index f16e610b44f32e9cc16c528743a0232d4ddf7e96..7a782cd7c2fcd22c9ad7aa3cd42b6a173fc7783d 100644
--- a/net/lwip/src/arch/sys_arch_init.c
+++ b/net/lwip/src/arch/sys_arch_init.c
@@ -23,6 +23,8 @@ void lwip_sys_init()
 	struct ip_addr ipaddr, netmask, gw;
 
 #if LWIP_DHCP
+	rt_uint32_t mscnt = 0;
+
 	IP4_ADDR(&gw, 0,0,0,0);
 	IP4_ADDR(&ipaddr, 0,0,0,0);
 	IP4_ADDR(&netmask, 0,0,0,0);
@@ -42,7 +44,7 @@ void lwip_sys_init()
 	dhcp_start(netif_default);
 
     while (1) {
-        sleep(DHCP_FINE_TIMER_MSECS);
+        rt_thread_delay(DHCP_FINE_TIMER_MSECS);
 
         dhcp_fine_tmr();
         mscnt += DHCP_FINE_TIMER_MSECS;