diff --git a/classes/Tools.php b/classes/Tools.php
index ee4036721..9e01065ad 100644
--- a/classes/Tools.php
+++ b/classes/Tools.php
@@ -2557,7 +2557,7 @@ exit;
 		$fileAttachment = null;
 		if (isset($_FILES[$input]['name']) && !empty($_FILES[$input]['name']) && !empty($_FILES[$input]['tmp_name']))
 		{
-			$fileAttachment['rename'] = uniqid(). self::strtolower(substr($_FILES[$input]['name'], -5));	
+			$fileAttachment['rename'] = uniqid(). Tools::strtolower(substr($_FILES[$input]['name'], -5));	
 			$fileAttachment['content'] = file_get_contents($_FILES[$input]['tmp_name']);
 			$fileAttachment['tmp_name'] = $_FILES[$input]['tmp_name'];
 			$fileAttachment['name'] = $_FILES[$input]['name'];
@@ -2592,4 +2592,4 @@ function cmpPriceDesc($a, $b)
 	elseif ((float)$a['price_tmp'] > (float)$b['price_tmp'])
 		return -1;
 	return 0;
-}
+}
\ No newline at end of file