--- a/plugins/muc/members_only.lib.lua	Wed Dec 08 16:40:51 2021 +0100
+++ b/plugins/muc/members_only.lib.lua	Wed Dec 08 21:02:14 2021 +0100
@@ -122,7 +122,6 @@
 		local affiliation = room:get_affiliation(stanza.attr.from);
 		if valid_affiliations[affiliation or "none"] <= valid_affiliations.none then
 			local reply = st.error_reply(stanza, "auth", "registration-required", nil, room.jid):up();
-			reply.tags[1].attr.code = "407";
 			event.origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
 			return true;
 		end

--- a/plugins/muc/muc.lib.lua	Wed Dec 08 16:40:51 2021 +0100
+++ b/plugins/muc/muc.lib.lua	Wed Dec 08 21:02:14 2021 +0100
@@ -449,7 +449,6 @@
 	local affiliation = room:get_affiliation(stanza.attr.from);
 	if affiliation == "outcast" then
 		local reply = st.error_reply(stanza, "auth", "forbidden", nil, room.jid):up();
-		reply.tags[1].attr.code = "403";
 		event.origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
 		return true;
 	end
@@ -692,7 +691,6 @@
 		-- new nick or has different bare real jid
 		log("debug", "%s couldn't join due to nick conflict: %s", real_jid, dest_occupant.nick);
 		local reply = st.error_reply(stanza, "cancel", "conflict", nil, self.jid):up();
-		reply.tags[1].attr.code = "409";
 		origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
 		return true;
 	end

--- a/plugins/muc/password.lib.lua	Wed Dec 08 16:40:51 2021 +0100
+++ b/plugins/muc/password.lib.lua	Wed Dec 08 21:02:14 2021 +0100
@@ -51,7 +51,6 @@
 		local from, to = stanza.attr.from, stanza.attr.to;
 		module:log("debug", "%s couldn't join due to invalid password: %s", from, to);
 		local reply = st.error_reply(stanza, "auth", "not-authorized", nil, room.jid):up();
-		reply.tags[1].attr.code = "401";
 		event.origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
 		return true;
 	end

--- a/spec/scansion/muc_password.scs	Wed Dec 08 16:40:51 2021 +0100
+++ b/spec/scansion/muc_password.scs	Wed Dec 08 21:02:14 2021 +0100
@@ -58,7 +58,7 @@
 
 Juliet receives:
 	<presence from="room@conference.localhost/Juliet" type="error">
-		<error type="auth" code="401" by="room@conference.localhost">
+		<error type="auth" by="room@conference.localhost">
 			<not-authorized xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
 		</error>
 	</presence>