diff --git a/usr.bin/perror/perror.c b/usr.bin/perror/perror.c
index e2453edc4577..9b7eda8d9f70 100644
--- a/usr.bin/perror/perror.c
+++ b/usr.bin/perror/perror.c
@@ -1,72 +1,73 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2009 Hudson River Trading LLC
  * Written by: George V. Neville-Neil <gnn@FreeBSD.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #include <sys/cdefs.h>
+#include <sys/errno.h>
+
+#include <err.h>
+#include <locale.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <err.h>
-#include <locale.h>
-#include <sys/errno.h>
 
 static void usage(void) __dead2;
 
 int 
 main(int argc, char **argv)
 {
 	char *cp;
 	char *errstr;
 	long errnum;
 
 	(void) setlocale(LC_MESSAGES, "");
 	if (argc != 2)
 		usage();
 
 	errno = 0;
 
 	errnum = strtol(argv[1], &cp, 0);
 
 	if (errno != 0)
 		err(EXIT_FAILURE, NULL);
 
 	if ((errstr = strerror(errnum)) == NULL) 
 		err(EXIT_FAILURE, NULL);
 
 	printf("%s\n", errstr);
 
 	exit(EXIT_SUCCESS);
 }
 
 static void 
 usage(void)
 {
 	fprintf(stderr, "usage: perror number\n");
 	exit(EXIT_FAILURE);
 }