diff --git a/libiberty/aclocal.m4 b/libiberty/aclocal.m4
index f327865aaf9..0757688d52a 100644
--- a/libiberty/aclocal.m4
+++ b/libiberty/aclocal.m4
@@ -1,6 +1,6 @@
-# generated automatically by aclocal 1.16.5 -*- Autoconf -*-
+# generated automatically by aclocal 1.15.1 -*- Autoconf -*-
 
-# Copyright (C) 1996-2021 Free Software Foundation, Inc.
+# Copyright (C) 1996-2017 Free Software Foundation, Inc.
 
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,