diff --git a/utf8.c b/utf8.c
--- a/utf8.c
+++ b/utf8.c
@@ -31,7 +31,7 @@
         dest[2] = 0;
         dest[3] = 0;
         if (wctomb (dest, (*str)) == -1)
-            return -1;
+            return EXIT_FAILURE;
 
         printf ("%lc -> [%4X] (%2X:%2X:%2X:%2X)\n",
                 *str, *str, (u_char) dest[0], (u_char) dest[1], (u_char) dest[2], (u_char) dest[3]);