diff --git a/htdocs/projet/class/project.class.php b/htdocs/projet/class/project.class.php
index f395173b327..7ee71bc1569 100644
--- a/htdocs/projet/class/project.class.php
+++ b/htdocs/projet/class/project.class.php
@@ -854,11 +854,24 @@ class Project extends CommonObject
 		$listoftables = array(
 			'propal'=>'fk_projet', 'commande'=>'fk_projet', 'facture'=>'fk_projet',
 			'supplier_proposal'=>'fk_projet', 'commande_fournisseur'=>'fk_projet', 'facture_fourn'=>'fk_projet',
-			'expensereport_det'=>'fk_projet', 'contrat'=>'fk_projet', 'fichinter'=>'fk_projet', 'don'=>'fk_projet',
-			'actioncomm'=>'fk_project', 'mrp_mo'=>'fk_project', 'entrepot'=>'fk_project'
+			'expensereport_det'=>'fk_projet', 'contrat'=>'fk_projet',
+			'fichinter'=>'fk_projet',
+			'don'=>array('field'=>'fk_projet', 'module'=>'don'),
+			'actioncomm'=>'fk_project',
+			'mrp_mo'=>'fk_project',
+			'entrepot'=>'fk_project'
 		);
 		foreach ($listoftables as $key => $value) {
-			$sql = "UPDATE ".MAIN_DB_PREFIX.$key." SET ".$value." = NULL where ".$value." = ".((int) $this->id);
+			if (is_array($value)) {
+				if (!isModEnabled($value['module'])) {
+					continue;
+				}
+				$fieldname = $value['field'];
+			} else {
+				$fieldname = $value;
+			}
+			$sql = "UPDATE ".MAIN_DB_PREFIX.$key." SET ".$fieldname." = NULL where ".$fieldname." = ".((int) $this->id);
+
 			$resql = $this->db->query($sql);
 			if (!$resql) {
 				$this->errors[] = $this->db->lasterror();