diff --git a/src/libutil-tests/monitorfdhup.cc b/src/libutil-tests/monitorfdhup.cc
index d591b2fed..02cd7e22c 100644
--- a/src/libutil-tests/monitorfdhup.cc
+++ b/src/libutil-tests/monitorfdhup.cc
@@ -1,4 +1,5 @@
-#ifndef _WIN32
+// TODO: investigate why this is hanging on cygwin
+#if !defined(_WIN32) && !defined(__CYGWIN__)
 
 #  include "nix/util/util.hh"
 #  include "nix/util/monitor-fd.hh"