--- a/plugins/mod_muc_mam.lua	Sat May 26 15:10:23 2018 +0200
+++ b/plugins/mod_muc_mam.lua	Tue May 29 04:24:43 2018 +0200
@@ -83,6 +83,7 @@
 
 	module:hook("muc-config-submitted/"..muc_form_enable, function(event)
 		event.room._data.archiving = event.value;
+		event.status_codes[event.value and "170" or "171"] = true;
 	end);
 end