1 files changed, 4 insertions, 4 deletions

diff --git a/gl/m4/mmap-anon.m4 b/gl/m4/mmap-anon.m4
index 9b60ddf..e47aa2d 100644
--- a/gl/m4/mmap-anon.m4
+++ b/gl/m4/mmap-anon.m4
@@ -1,5 +1,5 @@
-# mmap-anon.m4 serial 10
-dnl Copyright (C) 2005, 2007, 2009-2013 Free Software Foundation, Inc.
+# mmap-anon.m4 serial 12
+dnl Copyright (C) 2005, 2007, 2009-2021 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -9,11 +9,11 @@ dnl with or without modifications, as long as this notice is preserved.
 # - On Linux, AIX, OSF/1, Solaris, Cygwin, Interix, Haiku, both MAP_ANONYMOUS
 #   and MAP_ANON exist and have the same value.
 # - On HP-UX, only MAP_ANONYMOUS exists.
-# - On Mac OS X, FreeBSD, NetBSD, OpenBSD, only MAP_ANON exists.
+# - On Mac OS X, FreeBSD, NetBSD, OpenBSD, Minix, only MAP_ANON exists.
 # - On IRIX, neither exists, and a file descriptor opened to /dev/zero must be
 #   used.
 
-AC_DEFUN([gl_FUNC_MMAP_ANON],
+AC_DEFUN_ONCE([gl_FUNC_MMAP_ANON],
 [
   dnl Persuade glibc <sys/mman.h> to define MAP_ANONYMOUS.
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])