diff --git a/main.c b/main.c
index ca96728..bedae82 100644
--- a/main.c
+++ b/main.c
@@ -40,7 +40,7 @@ main(int argc, char *argv[])
                     break;
             }
     if (hlp) {
-        fprintf(stdout, "Usage: %s -d -h infile outfile\n", prog);
+        fprintf(stdout, "Usage: %s -duhw infile outfile\n", prog);
     } else {
         if (argc >= 1 && (in = fopen(*argv, "r")) == NULL) {
             fprintf(stderr, "%s: can't open %s\n", prog, *argv);