diff --git dmenu.c dmenu.c
index a07f8e3..98a0073 100644
--- dmenu.c
+++ dmenu.c
@@ -652,7 +652,7 @@ main(int argc, char *argv[])
 		else
 			usage();
 
-	if (!setlocale(LC_CTYPE, "") || !XSupportsLocale())
+	if (!setlocale(LC_CTYPE, NULL) || !XSupportsLocale())
 		fputs("warning: no locale support\n", stderr);
 	if (!(dpy = XOpenDisplay(NULL)))
 		die("cannot open display\n");