diff --git a/bureau/admin/index.php b/bureau/admin/index.php
index 6ed1193b..97f95c82 100644
--- a/bureau/admin/index.php
+++ b/bureau/admin/index.php
@@ -36,7 +36,7 @@ $H=getenv("HTTP_HOST");
 if (!isset($restrictip)) {
   $restrictip=1;
 }
-if (!$charset) $charset="UTF-8";
+if (!isset($charset) || ! $charset) $charset="UTF-8";
 @header("Content-Type: text/html; charset=$charset");
 
 ?>