diff -r 22bbc644c5eb -r f7e8d299513f plugins/mod_carbons.lua
--- a/plugins/mod_carbons.lua	Sun Apr 26 21:11:00 2020 +0200
+++ b/plugins/mod_carbons.lua	Sun Apr 26 20:23:50 2020 +0200
@@ -43,6 +43,10 @@
 		return true, "type";
 	end
 
+	if st_type == "error" and not c2s and not (stanza.attr.from or ""):find("/") then
+		return true, "bounce";
+	end
+
 	return false, "default";
 end