diff --git a/api/src/Db/Backup.php b/api/src/Db/Backup.php
index 1267ce9f54..a93d8cac4f 100644
--- a/api/src/Db/Backup.php
+++ b/api/src/Db/Backup.php
@@ -943,7 +943,7 @@ class Backup
 
 			if ($lock_table || empty($pk) && is_null($lock_table))
 			{
-				$this->db->Link_ID->RowLock($table);
+				$this->db->Link_ID->RowLock($table, 'true');	// PostgreSQL drive from ADOdb requires 2. param $where!
 			}
 			$total = $max = 0;
 			do {