diff --git a/htdocs/admin/tools/export.php b/htdocs/admin/tools/export.php
index c9e4211842d..c89fafbe052 100644
--- a/htdocs/admin/tools/export.php
+++ b/htdocs/admin/tools/export.php
@@ -1,6 +1,7 @@
 <?php
-/* Copyright (C) 2006-2014 Laurent Destailleur  <eldy@users.sourceforge.net>
- * Copyright (C) 2011	   Juanjo Menent		<jmenent@2byte.es>
+/* Copyright (C) 2006-2014  Laurent Destailleur <eldy@users.sourceforge.net>
+ * Copyright (C) 2011       Juanjo Menent       <jmenent@2byte.es>
+ * Copyright (C) 2015       Raphaël Doursenaud  <rdoursenaud@gpcsolutions.fr>
  *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
@@ -417,8 +418,14 @@ function backup_tables($outputfile, $tables='*')
     global $errormsg;
 
     // Set to UTF-8
-    $db->query('SET NAMES utf8');
-    $db->query('SET CHARACTER SET utf8');
+	if(is_a($db, 'DoliDBMysqli')) {
+		/** @var DoliDBMysqli $db */
+		$db->db->set_charset('utf8');
+	} else {
+		/** @var DoliDB $db */
+		$db->query('SET NAMES utf8');
+		$db->query('SET CHARACTER SET utf8');
+	}
 
     //get all of the tables
     if ($tables == '*')
diff --git a/htdocs/core/db/mysqli.class.php b/htdocs/core/db/mysqli.class.php
index 04f6372055f..05e84d6dd50 100644
--- a/htdocs/core/db/mysqli.class.php
+++ b/htdocs/core/db/mysqli.class.php
@@ -4,6 +4,7 @@
  * Copyright (C) 2004-2011	Laurent Destailleur		<eldy@users.sourceforge.net>
  * Copyright (C) 2006		Andre Cianfarani		<acianfa@free.fr>
  * Copyright (C) 2005-2012	Regis Houssin			<regis.houssin@capnetworks.com>
+ * Copyright (C) 2015       Raphaël Doursenaud      <rdoursenaud@gpcsolutions.fr>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -115,11 +116,9 @@ class DoliDBMysqli extends DoliDB
                 $clientmustbe='';
                 if (preg_match('/UTF-8/i',$conf->file->character_set_client))      $clientmustbe='utf8';
                 if (preg_match('/ISO-8859-1/i',$conf->file->character_set_client)) $clientmustbe='latin1';
-                if ($this->db->character_set_name() != $clientmustbe)
-                {
-                    $this->query("SET NAMES '".$clientmustbe."'", $this->db);
-                    //$this->query("SET CHARACTER SET ". $this->forcecharset);
-                }
+				if ($this->db->character_set_name() != $clientmustbe) {
+					$this->db->set_charset($clientmustbe);
+				}
             }
             else
             {
@@ -141,11 +140,9 @@ class DoliDBMysqli extends DoliDB
                 $clientmustbe='';
                 if (preg_match('/UTF-8/i',$conf->file->character_set_client))      $clientmustbe='utf8';
                 if (preg_match('/ISO-8859-1/i',$conf->file->character_set_client)) $clientmustbe='latin1';
-                if ($this->db->character_set_name() != $clientmustbe)
-                {
-                    $this->query("SET NAMES '".$clientmustbe."'", $this->db);
-                    //$this->query("SET CHARACTER SET ". $this->forcecharset);
-                }
+				if ($this->db->character_set_name() != $clientmustbe) {
+					$this->db->set_charset($clientmustbe);
+				}
             }
         }