diff --git a/admin/themes/default/template/profile_content.tpl b/admin/themes/default/template/profile_content.tpl
index 22be71cca..57dba40d1 100644
--- a/admin/themes/default/template/profile_content.tpl
+++ b/admin/themes/default/template/profile_content.tpl
@@ -55,6 +55,7 @@
         </span>
         <input type="text" size="3" maxlength="2" name="nb_line_page" id="nb_line_page" value="{$NB_ROW_PAGE}" >
       </li>
+{if not $SPECIAL_USER}
       <li>
         <span class="property">
           <label for="template">{'Interface theme'|@translate}</label>
@@ -67,6 +68,7 @@
         </span>
         {html_options id=language name=language options=$language_options selected=$language_selection}
       </li>
+{/if}
       <li>
         <span class="property">
           <label for="recent_period">{'Recent period'|@translate}</label>
diff --git a/profile.php b/profile.php
index ddc7a3452..8a36d131c 100644
--- a/profile.php
+++ b/profile.php
@@ -97,11 +97,14 @@ function save_profile_from_post($userdata, &$errors)
   $special_user = in_array($userdata['id'], array($conf['guest_id'], $conf['default_user_id']));
   if ($special_user)
   {
-    unset($_POST['mail_address'],
-          $_POST['password'],
-          $_POST['use_new_pwd'],
-          $_POST['passwordConf']
-          );
+    unset(
+      $_POST['mail_address'],
+      $_POST['password'],
+      $_POST['use_new_pwd'],
+      $_POST['passwordConf'],
+      $_POST['theme'],
+      $_POST['language']
+      );
   }
 
   if ($conf['allow_user_customization'] or defined('IN_ADMIN'))