diff --git a/doc/misc/options b/doc/misc/options
index 0aec7c5dea..5e5f808704 100644
--- a/doc/misc/options
+++ b/doc/misc/options
@@ -277,8 +277,8 @@ options {
 	sig-signing-signatures <integer>;
 	sig-signing-type <integer>;
 	sig-validity-interval <integer> [ <integer> ]; // obsolete
-	sig0checks-quota <integer>;
-	sig0checks-quota-exempt { <address_match_element>; ... };
+	sig0checks-quota <integer>; // experimental
+	sig0checks-quota-exempt { <address_match_element>; ... }; // experimental
 	sortlist { <address_match_element>; ... }; // deprecated
 	stale-answer-client-timeout ( disabled | off | <integer> );
 	stale-answer-enable <boolean>;
diff --git a/lib/isccfg/namedconf.c b/lib/isccfg/namedconf.c
index b9f8500d7a..a69c559f38 100644
--- a/lib/isccfg/namedconf.c
+++ b/lib/isccfg/namedconf.c
@@ -1361,8 +1361,9 @@ static cfg_clausedef_t options_clauses[] = {
 	{ "session-keyalg", &cfg_type_astring, 0 },
 	{ "session-keyfile", &cfg_type_qstringornone, 0 },
 	{ "session-keyname", &cfg_type_astring, 0 },
-	{ "sig0checks-quota", &cfg_type_uint32, 0 },
-	{ "sig0checks-quota-exempt", &cfg_type_bracketed_aml, 0 },
+	{ "sig0checks-quota", &cfg_type_uint32, CFG_CLAUSEFLAG_EXPERIMENTAL },
+	{ "sig0checks-quota-exempt", &cfg_type_bracketed_aml,
+	  CFG_CLAUSEFLAG_EXPERIMENTAL },
 	{ "sit-secret", NULL, CFG_CLAUSEFLAG_ANCIENT },
 	{ "stacksize", &cfg_type_size, CFG_CLAUSEFLAG_ANCIENT },
 	{ "startup-notify-rate", &cfg_type_uint32, 0 },