diff --git a/winsup/cygwin/fhandler_fifo.cc b/winsup/cygwin/fhandler_fifo.cc
index ab4b93942..3d34cdfab 100644
--- a/winsup/cygwin/fhandler_fifo.cc
+++ b/winsup/cygwin/fhandler_fifo.cc
@@ -1020,6 +1020,7 @@ err_close_reader:
   saved_errno = get_errno ();
   close ();
   set_errno (saved_errno);
+  reader_opening_unlock ();
   return 0;
 err_close_cancel_evt:
   NtClose (cancel_evt);