diff --git a/Quake/net_sys.h b/Quake/net_sys.h
index 508edd20..2978feb1 100644
--- a/Quake/net_sys.h
+++ b/Quake/net_sys.h
@@ -111,6 +111,9 @@ typedef int	socklen_t;
 #define	closesocket	close
 #endif
 
+#define	NET_EWOULDBLOCK		EWOULDBLOCK
+#define	NET_ECONNREFUSED	ECONNREFUSED
+
 #define	socketerror(x)	strerror((x))
 
 /* Verify that we defined HAVE_SA_LEN correctly: */
@@ -142,12 +145,8 @@ typedef int	socklen_t;
 typedef SOCKET	sys_socket_t;
 
 #define	SOCKETERRNO	WSAGetLastError()
-/* the new MS SDKs define the following two,
- * so we must undefine them before redefining. */
-#undef	EWOULDBLOCK
-#define	EWOULDBLOCK	WSAEWOULDBLOCK
-#undef	ECONNREFUSED
-#define	ECONNREFUSED	WSAECONNREFUSED
+#define	NET_EWOULDBLOCK		WSAEWOULDBLOCK
+#define	NET_ECONNREFUSED	WSAECONNREFUSED
 /* must #include "wsaerror.h" for this : */
 #define	socketerror(x)	__WSAE_StrError((x))
 
diff --git a/Quake/net_udp.c b/Quake/net_udp.c
index 38ceb954..c029383b 100644
--- a/Quake/net_udp.c
+++ b/Quake/net_udp.c
@@ -261,7 +261,7 @@ int UDP_Read (sys_socket_t socketid, byte *buf, int len, struct qsockaddr *addr)
 	if (ret == SOCKET_ERROR)
 	{
 		int err = SOCKETERRNO;
-		if (err == EWOULDBLOCK || err == ECONNREFUSED)
+		if (err == NET_EWOULDBLOCK || err == NET_ECONNREFUSED)
 			return 0;
 		Con_SafePrintf ("UDP_Read, recvfrom: %s\n", socketerror(err));
 	}
@@ -319,7 +319,7 @@ int UDP_Write (sys_socket_t socketid, byte *buf, int len, struct qsockaddr *addr
 	if (ret == SOCKET_ERROR)
 	{
 		int err = SOCKETERRNO;
-		if (err == EWOULDBLOCK)
+		if (err == NET_EWOULDBLOCK)
 			return 0;
 		Con_SafePrintf ("UDP_Write, sendto: %s\n", socketerror(err));
 	}
diff --git a/Quake/net_wins.c b/Quake/net_wins.c
index f1941f9c..cf4841c4 100644
--- a/Quake/net_wins.c
+++ b/Quake/net_wins.c
@@ -354,7 +354,7 @@ int WINS_Read (sys_socket_t socketid, byte *buf, int len, struct qsockaddr *addr
 	if (ret == SOCKET_ERROR)
 	{
 		int err = SOCKETERRNO;
-		if (err == EWOULDBLOCK || err == ECONNREFUSED)
+		if (err == NET_EWOULDBLOCK || err == NET_ECONNREFUSED)
 			return 0;
 		Con_SafePrintf ("WINS_Read, recvfrom: %s\n", socketerror(err));
 	}
@@ -413,7 +413,7 @@ int WINS_Write (sys_socket_t socketid, byte *buf, int len, struct qsockaddr *add
 	if (ret == SOCKET_ERROR)
 	{
 		int err = SOCKETERRNO;
-		if (err == EWOULDBLOCK)
+		if (err == NET_EWOULDBLOCK)
 			return 0;
 		Con_SafePrintf ("WINS_Write, sendto: %s\n", socketerror(err));
 	}
diff --git a/Quake/net_wipx.c b/Quake/net_wipx.c
index 0d6bdd24..afb6216f 100644
--- a/Quake/net_wipx.c
+++ b/Quake/net_wipx.c
@@ -251,7 +251,7 @@ int WIPX_Read (sys_socket_t handle, byte *buf, int len, struct qsockaddr *addr)
 	if (ret == SOCKET_ERROR)
 	{
 		int err = SOCKETERRNO;
-		if (err == EWOULDBLOCK || err == ECONNREFUSED)
+		if (err == NET_EWOULDBLOCK || err == NET_ECONNREFUSED)
 			return 0;
 		Con_SafePrintf ("WIPX_Read, recvfrom: %s\n", socketerror(err));
 	}
@@ -290,7 +290,7 @@ int WIPX_Write (sys_socket_t handle, byte *buf, int len, struct qsockaddr *addr)
 	if (ret == SOCKET_ERROR)
 	{
 		int err = SOCKETERRNO;
-		if (err == EWOULDBLOCK)
+		if (err == NET_EWOULDBLOCK)
 			return 0;
 		Con_SafePrintf ("WIPX_Write, sendto: %s\n", socketerror(err));
 	}