diff --git a/src/include/lwip/sockets.h b/src/include/lwip/sockets.h
index 4cb2b809..3f004d07 100644
--- a/src/include/lwip/sockets.h
+++ b/src/include/lwip/sockets.h
@@ -41,12 +41,12 @@
 
 #include "lwip/opt.h"
 
+#if LWIP_SOCKET /* don't build if not configured for use in lwipopts.h */
+
 #if LWIP_SOCKET_EXTERNAL_HEADERS
 #include LWIP_SOCKET_EXTERNAL_HEADER_SOCKETS_H
 #else /* LWIP_SOCKET_EXTERNAL_HEADERS */
 
-#if LWIP_SOCKET /* don't build if not configured for use in lwipopts.h */
-
 #include "lwip/ip_addr.h"
 #include "lwip/netif.h"
 #include "lwip/err.h"
@@ -534,6 +534,16 @@ struct timeval {
 };
 #endif /* LWIP_TIMEVAL_PRIVATE */
 
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LWIP_SOCKET_EXTERNAL_HEADERS */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define lwip_socket_init() /* Compatibility define, no init needed. */
 void lwip_socket_thread_init(void); /* LWIP_NETCONN_SEM_PER_THREAD==1: initialize thread-local semaphore */
 void lwip_socket_thread_cleanup(void); /* LWIP_NETCONN_SEM_PER_THREAD==1: destroy thread-local semaphore */
@@ -694,6 +704,4 @@ int lwip_inet_pton(int af, const char *src, void *dst);
 
 #endif /* LWIP_SOCKET */
 
-#endif /* LWIP_SOCKET_EXTERNAL_HEADERS */
-
 #endif /* LWIP_HDR_SOCKETS_H */