diff --git a/doc/misc/options b/doc/misc/options
index 6a193547a0..c5a5193183 100644
--- a/doc/misc/options
+++ b/doc/misc/options
@@ -302,7 +302,6 @@ options {
 	tcp-primaries-timeout <integer>;
 	tcp-receive-buffer <integer>;
 	tcp-send-buffer <integer>;
-	tkey-domain <quoted_string>; // obsolete
 	tkey-gssapi-keytab <quoted_string>;
 	tls-port <integer>;
 	transfer-format ( many-answers | one-answer );
diff --git a/lib/isccfg/namedconf.c b/lib/isccfg/namedconf.c
index cb4a36c2b6..f6df82d995 100644
--- a/lib/isccfg/namedconf.c
+++ b/lib/isccfg/namedconf.c
@@ -1348,7 +1348,7 @@ static cfg_clausedef_t options_clauses[] = {
 	{ "tcp-receive-buffer", &cfg_type_uint32, 0 },
 	{ "tcp-send-buffer", &cfg_type_uint32, 0 },
 	{ "tkey-dhkey", NULL, CFG_CLAUSEFLAG_ANCIENT },
-	{ "tkey-domain", &cfg_type_qstring, CFG_CLAUSEFLAG_OBSOLETE },
+	{ "tkey-domain", &cfg_type_qstring, CFG_CLAUSEFLAG_ANCIENT },
 	{ "tkey-gssapi-credential", &cfg_type_qstring, CFG_CLAUSEFLAG_ANCIENT },
 	{ "tkey-gssapi-keytab", &cfg_type_qstring, 0 },
 	{ "transfer-message-size", &cfg_type_uint32, 0 },