diff --git a/grep.c b/grep.c
index 64ffbe2..22b3b6f 100644
--- a/grep.c
+++ b/grep.c
@@ -1,4 +1,5 @@
 /* See LICENSE file for copyright and license details. */
+#include <locale.h>
 #include <regex.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -178,6 +179,8 @@ main(int argc, char *argv[])
 	FILE *fp;
 	char *arg;
 
+	setlocale(LC_ALL, "");
+
 	SLIST_INIT(&phead);
 
 	ARGBEGIN {