diff --git a/locales/en.json b/locales/en.json
index 1d68fb334..73b5c46fb 100644
--- a/locales/en.json
+++ b/locales/en.json
@@ -429,6 +429,7 @@
     "permission_update_failed": "Could not update permission '{permission}' : {error}",
     "permission_updated": "Permission '{permission:s}' updated",
     "permission_update_nothing_to_do": "No permissions to update",
+    "permission_require_account": "Permission {permission} only makes sense for users having an account, and therefore cannot be enabled for visitors.",
     "port_already_closed": "Port {port:d} is already closed for {ip_version:s} connections",
     "port_already_opened": "Port {port:d} is already opened for {ip_version:s} connections",
     "port_available": "Port {port:d} is available",
diff --git a/src/yunohost/permission.py b/src/yunohost/permission.py
index 67d115bc7..226cc9050 100644
--- a/src/yunohost/permission.py
+++ b/src/yunohost/permission.py
@@ -100,6 +100,10 @@ def user_permission_update(operation_logger, permission, add=None, remove=None,
     if "." not in permission:
         permission = permission + ".main"
 
+    # Refuse to add "visitors" to mail, xmpp ... they require an account to make sense.
+    if add and "visitors" in add and permission.split(".")[0] in SYSTEM_PERMS:
+        raise YunohostError('permission_require_account', permission=permission)
+
     # Fetch currently allowed groups for this permission
 
     existing_permission = user_permission_list(full=True)["permissions"].get(permission, None)