diff --git a/components/net/lwip-2.1/porting/include/lwip/netdb.h b/components/net/lwip-2.1/porting/include/lwip/netdb.h
index 0533eb329869fae7d9f8a1dcc00f8063a3fd5f69..8edbc35a04f9670d4c6f7c482c9618e608bd4bd9 100644
--- a/components/net/lwip-2.1/porting/include/lwip/netdb.h
+++ b/components/net/lwip-2.1/porting/include/lwip/netdb.h
@@ -34,6 +34,8 @@
 
 #include "lwip/arch.h"
 #include <netdb.h>
+#undef h_errno
+#undef LWIP_DNS_API_DECLARE_H_ERRNO
 #include_next <lwip/netdb.h>
 
 #endif /* _LWIP_PORTING_NETDB_H_ */