diff --git a/src/libCom/osi/osiSock.h b/src/libCom/osi/osiSock.h
index 957565586..17d1b8b7a 100644
--- a/src/libCom/osi/osiSock.h
+++ b/src/libCom/osi/osiSock.h
@@ -107,6 +107,10 @@ epicsShareFunc const char * epicsShareAPI convertSocketErrorToString (int errnoI
 
 #include "osdSock.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef union osiSockAddr {
     struct sockaddr_in  ia;
     struct sockaddr     sa;
@@ -156,4 +160,8 @@ epicsShareFunc void epicsShareAPI osiSockDiscoverBroadcastAddresses
  */
 epicsShareFunc osiSockAddr epicsShareAPI osiLocalAddr (SOCKET socket);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* ifndef osiSockh */