--- Python-3.8.5/Modules/socketmodule.h.orig	2020-07-20 15:01:32.000000000 +0200
+++ Python-3.8.5/Modules/socketmodule.h	2020-07-23 09:32:42.727747500 +0200
@@ -8,9 +8,7 @@
 #   include <sys/socket.h>
 # endif
 # include <netinet/in.h>
-# if !defined(__CYGWIN__)
-#  include <netinet/tcp.h>
-# endif
+# include <netinet/tcp.h>
 
 #else /* MS_WINDOWS */
 # include <winsock2.h>
