diff --git a/components/lwip/apps/dhcpserver/dhcpserver.c b/components/lwip/apps/dhcpserver/dhcpserver.c
index 5e0c1a678..7997eb419 100644
--- a/components/lwip/apps/dhcpserver/dhcpserver.c
+++ b/components/lwip/apps/dhcpserver/dhcpserver.c
@@ -341,18 +341,20 @@ static u8_t *add_offer_options(u8_t *optptr)
         }
     }
 
-    *optptr++ = DHCP_OPTION_DNS_SERVER;
-    *optptr++ = 4;
     if (dhcps_dns_enabled(dhcps_dns)) {
-        *optptr++ = ip4_addr1(&dns_server);
-        *optptr++ = ip4_addr2(&dns_server);
-        *optptr++ = ip4_addr3(&dns_server);
-        *optptr++ = ip4_addr4(&dns_server);
-    }else {
-        *optptr++ = ip4_addr1(&ipadd);
-        *optptr++ = ip4_addr2(&ipadd);
-        *optptr++ = ip4_addr3(&ipadd);
-        *optptr++ = ip4_addr4(&ipadd);
+        *optptr++ = DHCP_OPTION_DNS_SERVER;
+        *optptr++ = 4;
+        if (dns_server.addr != IPADDR_ANY) {
+            *optptr++ = ip4_addr1(&dns_server);
+            *optptr++ = ip4_addr2(&dns_server);
+            *optptr++ = ip4_addr3(&dns_server);
+            *optptr++ = ip4_addr4(&dns_server);
+        } else {
+            *optptr++ = ip4_addr1(&ipadd);
+            *optptr++ = ip4_addr2(&ipadd);
+            *optptr++ = ip4_addr3(&ipadd);
+            *optptr++ = ip4_addr4(&ipadd);
+        }
     }
 
 #ifdef CLASS_B_NET
@@ -1110,7 +1112,7 @@ static void dhcps_poll_set(u32_t ip)
 
 /******************************************************************************
  * FunctionName : dhcps_set_new_lease_cb
- * Description  : set callback for dhcp server when it assign an IP 
+ * Description  : set callback for dhcp server when it assign an IP
  *                to the connected dhcp client
  * Parameters   : cb -- callback for dhcp server
  * Returns      : none
@@ -1306,7 +1308,7 @@ dhcps_dns_setserver(const ip_addr_t *dnsserver)
         dns_server = *(ip_2_ip4(dnsserver));
     } else {
         dns_server = *(ip_2_ip4(IP_ADDR_ANY));
-    } 
+    }
 }
 
 /******************************************************************************
@@ -1315,7 +1317,7 @@ dhcps_dns_setserver(const ip_addr_t *dnsserver)
  * Parameters   : none
  * Returns      : ip4_addr_t
 *******************************************************************************/
-ip4_addr_t 
+ip4_addr_t
 dhcps_dns_getserver()
 {
     return dns_server;