diff --git a/e_os.h b/e_os.h
index 0f4b7994f..48ed6bdff 100644
--- a/e_os.h
+++ b/e_os.h
@@ -150,6 +150,9 @@ extern "C" {
 #define clear_socket_error()	WSASetLastError(0)
 #define readsocket(s,b,n)	recv((s),(b),(n),0)
 #define writesocket(s,b,n)	send((s),(b),(n),0)
+#ifdef EADDRINUSE
+#undef EADDRINUSE
+#endif
 #define EADDRINUSE		WSAEADDRINUSE
 #elif defined(__DJGPP__)
 #define WATT32