diff --git a/src/Network/native_fdm.cxx b/src/Network/native_fdm.cxx
index 0afba9cfe..5af740b17 100644
--- a/src/Network/native_fdm.cxx
+++ b/src/Network/native_fdm.cxx
@@ -25,7 +25,7 @@
 #  include <config.h>
 #endif
 
-#ifdef WIN32
+#if defined(WIN32) && !defined(__CYGWIN__)
 #  include <windows.h>
 #else
 #  include <netinet/in.h>	// htonl() ntohl()