diff --git a/src/main/help.c b/src/main/help.c
index 633b4ae..cd74f73 100644
--- a/src/main/help.c
+++ b/src/main/help.c
@@ -357,7 +357,7 @@ void display_help(void)
 		{ "-U", "--store-and-forward", N_("FILE"),
 		 N_("write all input to FILE before writing to output"),
 		 { 0, 0, 0, 0} },
-		{ "-d", "--watchfd", N_("PID[:FD]"),
+		{ "-d", "--watchfd", N_("PID[:FD]|=NAME|@LISTFILE"),
 		 N_("watch file FD opened by process PID"),
 		 { 0, 0, 0, 0} },
 #ifdef PV_REMOTE_CONTROL