diff --git a/doc/bird.sgml b/doc/bird.sgml
index 3c58e760..c7d8b792 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -1390,7 +1390,7 @@ protocol ospf <name> {
 			wait <num>;
 			dead count <num>;
 			dead <num>;
-			authentication [none|simple];
+			authentication [none|simple|cryptographics];
 			password "<text>";
 		};
 	};