diff --git a/monitor/main.c b/monitor/main.c
index fd3954b..e124157 100644
--- a/monitor/main.c
+++ b/monitor/main.c
@@ -63,6 +63,7 @@ static void usage(void)
 		"\t-s, --server <socket>  Start monitor server socket\n"
 		"\t-p, --priority <level> Show only priority or lower\n"
 		"\t-i, --index <num>      Show only specified controller\n"
+		"\t-d, --tty <tty>        Read data from TTY\n"
 		"\t-t, --time             Show time instead of time offset\n"
 		"\t-T, --date             Show time and date information\n"
 		"\t-S, --sco              Dump SCO traffic\n"