diff --git a/htdocs/projet/class/task.class.php b/htdocs/projet/class/task.class.php
index f7688bec28334..b3872bdb35db6 100644
--- a/htdocs/projet/class/task.class.php
+++ b/htdocs/projet/class/task.class.php
@@ -587,6 +587,7 @@ public function fetch($id, $ref = '', $loadparentdata = 0)
 			$this->db->free($resql);
 
 			if ($num_rows) {
+				$this->oldcopy = clone $this;
 				return 1;
 			} else {
 				return 0;