diff --git a/config_panel.toml b/config_panel.toml
index 2a32a20..1f1f871 100644
--- a/config_panel.toml
+++ b/config_panel.toml
@@ -21,5 +21,5 @@ help = "Here you can easily configure some things about your Fluffychat instance
         help.en = "This option changes the default Matrix server on the Fluffychat login page."
         help.fr = "Cette option modifie le serveur Matrix renseigné par défaut sur la page de connexion de Fluffychat."
         type = "string"
-        pattern.regexp = '^([-?a-zA-Z0-9]\.?){1,256}[a-zA-Z0-9]{1,6}$'
+        pattern.regexp = '^([-?a-zA-Z0-9]\.?){1,256}(\.[a-zA-Z0-9]{1,6}){1}$'
         pattern.error = "Must be a domain name or a sub-domain. Must not start with 'http://' or 'https://'."