diff --git a/usr.bin/vis/vis.c b/usr.bin/vis/vis.c
index 1706801e334d..494ae5719bcc 100644
--- a/usr.bin/vis/vis.c
+++ b/usr.bin/vis/vis.c
@@ -43,6 +43,7 @@ static char sccsid[] = "@(#)vis.c	8.1 (Berkeley) 6/6/93";
 
 #include <stdio.h>
 #include <vis.h>
+#include <locale.h>
 
 int eflags, fold, foldwidth=80, none, markeol, debug;
 
@@ -55,6 +56,8 @@ main(argc, argv)
 	FILE *fp;
 	int ch;
 
+	(void) setlocale(LC_CTYPE, "");
+
 	while ((ch = getopt(argc, argv, "nwctsobfF:ld")) != EOF)
 		switch((char)ch) {
 		case 'n':