diff --git a/src/ca/tcpiiu.cpp b/src/ca/tcpiiu.cpp
index 3f37f58f2..eb193d0bb 100644
--- a/src/ca/tcpiiu.cpp
+++ b/src/ca/tcpiiu.cpp
@@ -636,7 +636,7 @@ void tcpiiu::shutdown ( epicsGuard <cacMutex > & guard )
         // linux threads in recv() dont wakeup unless we also
         // call shutdown ( close() by itself is not enough )
         if ( oldState == iiucs_connected ) {
-            int status = ::shutdown ( this->sock, SD_BOTH );
+            int status = ::shutdown ( this->sock, SHUT_RDWR );
             if ( status ) {
                 errlogPrintf ("CAC TCP socket shutdown error was %s\n", 
                     SOCKERRSTR (SOCKERRNO) );
diff --git a/src/cas/io/bsdSocket/casStreamIO.cc b/src/cas/io/bsdSocket/casStreamIO.cc
index e4d08b122..188ed208c 100644
--- a/src/cas/io/bsdSocket/casStreamIO.cc
+++ b/src/cas/io/bsdSocket/casStreamIO.cc
@@ -183,7 +183,7 @@ void casStreamIO::forceDisconnect ()
 {
 	if ( ! this->sockHasBeenClosed ) {
         this->sockHasBeenClosed = true;
-        int status = ::shutdown ( this->sock, SD_BOTH );
+        int status = ::shutdown ( this->sock, SHUT_RDWR );
         if ( status ) {
             errlogPrintf ("CAC TCP socket shutdown error was %s\n", 
                 SOCKERRSTR (SOCKERRNO) );
diff --git a/src/libCom/osi/os/Darwin/osdSock.h b/src/libCom/osi/os/Darwin/osdSock.h
index a4ee29cd1..27a1d19ea 100644
--- a/src/libCom/osi/os/Darwin/osdSock.h
+++ b/src/libCom/osi/os/Darwin/osdSock.h
@@ -68,8 +68,8 @@ typedef int osiSocklen_t;
 #define SOCK_ENOTSOCK ENOTSOCK
 #define SOCK_EBADF EBADF
 
-#ifndef SD_BOTH
-#define SD_BOTH 2
+#ifndef SHUT_RDWR
+#define SHUT_RDWR 2
 #endif
 
 #define ifreq_size(pifreq) ((pifreq)->ifr_addr.sa_len + sizeof((pifreq)->ifr_name))
diff --git a/src/libCom/osi/os/Linux/osdSock.h b/src/libCom/osi/os/Linux/osdSock.h
index 07a0c9313..bd993e0c1 100644
--- a/src/libCom/osi/os/Linux/osdSock.h
+++ b/src/libCom/osi/os/Linux/osdSock.h
@@ -81,8 +81,8 @@ typedef socklen_t osiSocklen_t;
 #define SOCK_ENOTSOCK ENOTSOCK
 #define SOCK_EBADF EBADF
 
-#ifndef SD_BOTH
-#define SD_BOTH 2
+#ifndef SHUT_RDWR
+#   define SHUT_RDWR 2
 #endif
 
 #define ifreq_size(pifreq) (sizeof(pifreq->ifr_name))
diff --git a/src/libCom/osi/os/RTEMS/osdSock.h b/src/libCom/osi/os/RTEMS/osdSock.h
index 75dd962ea..8147e7f2a 100644
--- a/src/libCom/osi/os/RTEMS/osdSock.h
+++ b/src/libCom/osi/os/RTEMS/osdSock.h
@@ -80,7 +80,9 @@ typedef int osiSocklen_t;
 /*
  * For shutdown()
  */
-#define SD_BOTH	2
+#ifndef SHUT_RDWR
+#   define SHUT_RDWR 2
+#endif
 
 /*
  * Ensure that we get the right network code in default/osdNetIntf.c.
diff --git a/src/libCom/osi/os/WIN32/osdSock.h b/src/libCom/osi/os/WIN32/osdSock.h
index a701c1083..1821d6ae6 100644
--- a/src/libCom/osi/os/WIN32/osdSock.h
+++ b/src/libCom/osi/os/WIN32/osdSock.h
@@ -37,6 +37,10 @@ extern "C" {
 typedef u_long FAR osiSockIoctl_t;
 typedef int osiSocklen_t;
 
+#ifndef SHUT_RDWR
+#   define SHUT_RDWR SD_BOTH
+#endif
+
 #define MAXHOSTNAMELEN		75
 #define IPPORT_USERRESERVED	5000U
 
diff --git a/src/libCom/osi/os/hpux/osdSock.h b/src/libCom/osi/os/hpux/osdSock.h
index 0d00c12c7..f85619c4f 100644
--- a/src/libCom/osi/os/hpux/osdSock.h
+++ b/src/libCom/osi/os/hpux/osdSock.h
@@ -71,8 +71,8 @@ typedef int osiSocklen_t;
 #define SOCK_ENOTSOCK ENOTSOCK
 #define SOCK_EBADF EBADF
 
-#ifndef SD_BOTH
-#define SD_BOTH 2
+#ifndef SHUT_RDWR
+#   define SHUT_RDWR 2
 #endif
 
 #define ifreq_size(pifreq) (sizeof(pifreq->ifr_name))
diff --git a/src/libCom/osi/os/solaris/osdSock.h b/src/libCom/osi/os/solaris/osdSock.h
index 41ea56cfa..865a2c93b 100644
--- a/src/libCom/osi/os/solaris/osdSock.h
+++ b/src/libCom/osi/os/solaris/osdSock.h
@@ -75,8 +75,8 @@ typedef int osiSockIoctl_t;
 #define SOCK_ENOTSOCK ENOTSOCK
 #define SOCK_EBADF EBADF
 
-#ifndef SD_BOTH
-#define SD_BOTH 2
+#ifndef SHUT_RDWR
+#   define SHUT_RDWR 2
 #endif
 
 #define ifreq_size(pifreq) (sizeof(pifreq->ifr_name))
diff --git a/src/libCom/osi/os/vxWorks/osdSock.h b/src/libCom/osi/os/vxWorks/osdSock.h
index baac6b284..11b1f0a4a 100644
--- a/src/libCom/osi/os/vxWorks/osdSock.h
+++ b/src/libCom/osi/os/vxWorks/osdSock.h
@@ -45,7 +45,9 @@ typedef int                     SOCKET;
 #define SOCKERRNO               errno
 #define SOCKERRSTR(ERRNO_IN)    (strerror(ERRNO_IN))
 #define socket_close(S)         close(S)
-#define SD_BOTH 2
+#ifndef SHUT_RDWR
+#   define SHUT_RDWR 2
+#endif
 
 /*
  * it is quite lame on WRS's part to assume that