Adde missing extern "C"
diff --git a/src/include/lwip/netdb.h b/src/include/lwip/netdb.h
index 54a1eb8..7587e2f 100644
--- a/src/include/lwip/netdb.h
+++ b/src/include/lwip/netdb.h
@@ -38,6 +38,10 @@
 #include "lwip/inet.h"
 #include "lwip/sockets.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* some rarely used options */
 #ifndef LWIP_DNS_API_DECLARE_H_ERRNO
 #define LWIP_DNS_API_DECLARE_H_ERRNO 1
@@ -111,6 +115,10 @@
        lwip_getaddrinfo(nodname, servname, hints, res)
 #endif /* LWIP_COMPAT_SOCKETS */
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* LWIP_DNS && LWIP_SOCKET */
 
 #endif /* __LWIP_NETDB_H__ */