diff --git a/src/ttysolitaire.c b/src/ttysolitaire.c
index 23d3026..2b0f192 100644
--- a/src/ttysolitaire.c
+++ b/src/ttysolitaire.c
@@ -22,9 +22,10 @@ void draw_greeting() {
 }
 
 void usage() {
-  printf("usage: %s [-v|--version] [-h|--help]\n", program_name);
+  printf("usage: %s [-v|--version] [-h|--help] [-p|--passes=NUMBER]\n", program_name);
   printf("  -v, --version  Show the version\n");
   printf("  -h, --help     Show this message\n");
+  printf("  -p, --passes   Number of passes through the deck\n");
 }
 
 void version() {