diff --git a/lib/un.rb b/lib/un.rb
index 3ef7375dd8..d109a3417b 100644
--- a/lib/un.rb
+++ b/lib/un.rb
@@ -313,6 +313,8 @@ end
 #   --do-not-reverse-lookup     disable reverse lookup
 #   --request-timeout=SECOND    request timeout in seconds
 #   --http-version=VERSION      HTTP version
+#   --server-name=NAME          name of the server host
+#   --server-software=NAME      name and version of the server
 #   --ssl-certificate=CERT      The SSL certificate file for the server
 #   --ssl-private-key=KEY       The SSL private key file for the server certificate
 #   -v                          verbose