diff --git a/bureau/admin/adm_login.php b/bureau/admin/adm_login.php
index fd9e76dc..088f0a9f 100644
--- a/bureau/admin/adm_login.php
+++ b/bureau/admin/adm_login.php
@@ -58,6 +58,13 @@ if ( empty($id) && isset($_COOKIE["oldid"]) && !empty($_COOKIE["oldid"])) {
     exit();
   }
 
+  if ($r['lastip'] != get_remote_ip() ) {
+    $error=_("Your IP is incorrect.");
+    include("index.php");
+    exit();
+  }
+  // FIXME we should add a peremption date on the cookie
+
   // Ok, so we remove the cookie : 
   setcookie('oldid','',0,'/');
   unset($_COOKIE['oldid']);
@@ -68,6 +75,7 @@ if ( empty($id) && isset($_COOKIE["oldid"]) && !empty($_COOKIE["oldid"])) {
     include("index.php");
     exit();
   }
+
   include_once("adm_list.php");
   exit();
 }
diff --git a/bureau/class/m_mem.php b/bureau/class/m_mem.php
index 76386e13..cc20f314 100644
--- a/bureau/class/m_mem.php
+++ b/bureau/class/m_mem.php
@@ -119,6 +119,8 @@ class m_mem {
     } else $ip="''";
     /* Close sessions that are more than 2 days old. */
     $db->query("DELETE FROM sessions WHERE DATE_ADD(ts,INTERVAL 2 DAY)<NOW();");
+    /* Delete old impersonation */
+    if ( isset($_COOKIE["oldid"]) ) setcookie('oldid','',0,'/'); 
     /* Open the session : */
     $sess=md5(uniqid(mt_rand()));
     $_REQUEST["session"]=$sess;