diff --git a/flags.go b/flags.go
index fb0d1fd..de3aead 100644
--- a/flags.go
+++ b/flags.go
@@ -97,7 +97,7 @@
 //     command:              when specified on a struct field, makes the struct
 //                           field a (sub)command with the given name (optional)
 //     subcommands-optional: when specified on a command struct field, makes
-//                           any subcommands of that command optional
+//                           any subcommands of that command optional (optional)
 //
 // Either short: or long: must be specified to make the field eligible as an
 // option.