diff --git a/htdocs/blockedlog/class/blockedlog.class.php b/htdocs/blockedlog/class/blockedlog.class.php
index 3c6f7563590..4da28dfdeb9 100644
--- a/htdocs/blockedlog/class/blockedlog.class.php
+++ b/htdocs/blockedlog/class/blockedlog.class.php
@@ -1,6 +1,6 @@
 <?php
-/* Copyright (C) 2017 ATM Consulting      <contact@atm-consulting.fr>
- * Copyright (C) 2017 Laurent Destailleur <eldy@destailleur.fr>
+/* Copyright (C) 2017      ATM Consulting      <contact@atm-consulting.fr>
+ * Copyright (C) 2017-2020 Laurent Destailleur <eldy@destailleur.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
@@ -115,6 +115,8 @@ class BlockedLog
 	public $ref_object = '';
 
 	public $object_data = null;
+	public $object_version = '';
+
 	public $user_fullname = '';
 
 	/**
@@ -674,7 +676,7 @@ class BlockedLog
 		$langs->load("blockedlog");
 
 		$sql = "SELECT b.rowid, b.date_creation, b.signature, b.signature_line, b.amounts, b.action, b.element, b.fk_object, b.entity,";
-		$sql .= " b.certified, b.tms, b.fk_user, b.user_fullname, b.date_object, b.ref_object, b.object_data";
+		$sql .= " b.certified, b.tms, b.fk_user, b.user_fullname, b.date_object, b.ref_object, b.object_data, b.object_version";
 		$sql .= " FROM ".MAIN_DB_PREFIX."blockedlog as b";
 		if ($id) $sql .= " WHERE b.rowid = ".$id;
 
@@ -704,6 +706,7 @@ class BlockedLog
 				$this->user_fullname = $obj->user_fullname;
 
 				$this->object_data = $this->dolDecodeBlockedData($obj->object_data);
+				$this->object_version = $obj->object_version;
 
 				$this->signature		= $obj->signature;
 				$this->signature_line = $obj->signature_line;
@@ -826,6 +829,7 @@ class BlockedLog
 		$sql .= " date_object,";
 		$sql .= " ref_object,";
 		$sql .= " object_data,";
+		$sql .= " object_version,";
 		$sql .= " certified,";
 		$sql .= " fk_user,";
 		$sql .= " user_fullname,";
@@ -841,6 +845,7 @@ class BlockedLog
 		$sql .= "'".$this->db->idate($this->date_object)."',";
 		$sql .= "'".$this->db->escape($this->ref_object)."',";
 		$sql .= "'".$this->db->escape(serialize($this->object_data))."',";
+		$sql .= "'".$this->db->escape($this->object_version)."',";
 		$sql .= "0,";
 		$sql .= $this->fk_user.",";
 		$sql .= "'".$this->db->escape($this->user_fullname)."',";
@@ -914,7 +919,11 @@ class BlockedLog
 	private function buildKeyForSignature()
 	{
 		//print_r($this->object_data);
-		return $this->date_creation.'|'.$this->action.'|'.$this->amounts.'|'.$this->ref_object.'|'.$this->date_object.'|'.$this->user_fullname.'|'.print_r($this->object_data, true);
+		if (((int) $this->object_version) > 12) {
+			return $this->date_creation.'|'.$this->action.'|'.$this->amounts.'|'.$this->ref_object.'|'.$this->date_object.'|'.$this->user_fullname.'|'.print_r($this->object_data, true);
+		} else {
+			return $this->date_creation.'|'.$this->action.'|'.$this->amounts.'|'.$this->ref_object.'|'.$this->date_object.'|'.$this->user_fullname.'|'.print_r($this->object_data, true);
+		}
 	}
 
 
diff --git a/htdocs/install/mysql/migration/11.0.0-12.0.0.sql b/htdocs/install/mysql/migration/11.0.0-12.0.0.sql
index fade1208c9c..0d0a3a23fae 100644
--- a/htdocs/install/mysql/migration/11.0.0-12.0.0.sql
+++ b/htdocs/install/mysql/migration/11.0.0-12.0.0.sql
@@ -203,3 +203,5 @@ ALTER TABLE llx_categorie MODIFY type integer NOT NULL DEFAULT 1;
 
 ALTER TABLE llx_societe_remise_except ADD COLUMN vat_src_code varchar(10) DEFAULT '';
 
+ALTER TABLE llx_blockedlog ADD COLUMN object_version varchar(32) DEFAULT '';
+
diff --git a/htdocs/install/mysql/tables/llx_blockedlog.sql b/htdocs/install/mysql/tables/llx_blockedlog.sql
index cf1db2e329e..09adfaf15d1 100644
--- a/htdocs/install/mysql/tables/llx_blockedlog.sql
+++ b/htdocs/install/mysql/tables/llx_blockedlog.sql
@@ -33,6 +33,7 @@ CREATE TABLE llx_blockedlog
 	signature varchar(100) NOT NULL, 
 	signature_line varchar(100) NOT NULL, 
 	object_data	text,
+	object_version varchar(32) DEFAULT '';
 	certified integer
 ) ENGINE=innodb;