--- ruby-2.3.4/thread.c	2017-03-27 18:54:09.000000000 +0200
+++ ruby-2.3.4/thread.c.api_break	2017-06-18 19:25:49.671240689 +0200
@@ -2187,6 +2187,12 @@
     return busy;
 }
 
+void
+rb_thread_fd_close(int fd)
+{
+    while (rb_notify_fd_close(fd));
+}
+
 /*
  *  call-seq:
  *     thr.raise