diff --git a/libvncclient/sasl.c b/libvncclient/sasl.c
index 0530307..db240c1 100644
--- a/libvncclient/sasl.c
+++ b/libvncclient/sasl.c
@@ -41,6 +41,9 @@
 #ifdef WIN32
 #undef SOCKET
 #include <winsock2.h>
+#ifdef EWOULDBLOCK
+#undef EWOULDBLOCK
+#endif
 #define EWOULDBLOCK WSAEWOULDBLOCK
 #define socklen_t int
 #define close closesocket
diff --git a/libvncclient/sockets.c b/libvncclient/sockets.c
index ed2deef..f042472 100644
--- a/libvncclient/sockets.c
+++ b/libvncclient/sockets.c
@@ -40,6 +40,9 @@
 #ifdef WIN32
 #undef SOCKET
 #include <winsock2.h>
+#ifdef EWOULDBLOCK
+#undef EWOULDBLOCK
+#endif
 #define EWOULDBLOCK WSAEWOULDBLOCK
 #define close closesocket
 #define read(sock,buf,len) recv(sock,buf,len,0)
diff --git a/libvncserver/sockets.c b/libvncserver/sockets.c
index bbc3d90..fe54a37 100644
--- a/libvncserver/sockets.c
+++ b/libvncserver/sockets.c
@@ -109,7 +109,13 @@ int deny_severity=LOG_WARNING;
 #pragma warning (disable: 4018 4761)
 #endif
 #define read(sock,buf,len) recv(sock,buf,len,0)
+#ifdef EWOULDBLOCK
+#undef EWOULDBLOCK
+#endif
 #define EWOULDBLOCK WSAEWOULDBLOCK
+#ifdef ETIMEDOUT
+#undef ETIMEDOUT
+#endif
 #define ETIMEDOUT WSAETIMEDOUT
 #define write(sock,buf,len) send(sock,buf,len,0)
 #else