diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
index b7f39ea3d499e4..9867f077faef7a 100644
--- a/Modules/_posixsubprocess.c
+++ b/Modules/_posixsubprocess.c
@@ -63,7 +63,7 @@
 # endif
 #endif
 
-#if defined(__FreeBSD__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__DragonFly__)
+#if defined(__CYGWIN__) || defined(__FreeBSD__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__DragonFly__)
 # define FD_DIR "/dev/fd"
 #else
 # define FD_DIR "/proc/self/fd"