diff --git a/htdocs/core/tpl/massactions_pre.tpl.php b/htdocs/core/tpl/massactions_pre.tpl.php
index 724ebae500bac..47f2c34b5e39a 100644
--- a/htdocs/core/tpl/massactions_pre.tpl.php
+++ b/htdocs/core/tpl/massactions_pre.tpl.php
@@ -71,15 +71,11 @@
 @phan-var-force string $search_all
 ';
 
-if (!isset($taskstatic) || !is_object($taskstatic)) {
+if (!is_object($taskstatic ?? null)) {
 	$taskstatic = null;
 }
-if (!isset($trackid)) {
-	$trackid = '';
-}
-if (!isset($modelmail)) {
-	$modelmail = '';
-}
+$trackid = (string) ($trackid ?? '');
+$modelmail = (string) ($modelmail ?? '');
 
 if (!empty($sall) || !empty($search_all)) {
 	$search_all = empty($sall) ? $search_all : $sall;
diff --git a/htdocs/projet/tasks.php b/htdocs/projet/tasks.php
index 81b8c42866f12..1eaf227dfb2a9 100644
--- a/htdocs/projet/tasks.php
+++ b/htdocs/projet/tasks.php
@@ -1065,7 +1065,7 @@
 	$linktotasks .= dolGetButtonTitle($langs->trans('ViewGantt'), '', 'fa fa-stream imgforviewmode', DOL_URL_ROOT.'/projet/ganttview.php?id='.$object->id.'&withproject=1', '', 1, array('morecss' => 'reposition marginleftonly'));
 
 	//print_barre_liste($title, 0, $_SERVER["PHP_SELF"], '', $sortfield, $sortorder, $linktotasks, $num, $totalnboflines, 'generic', 0, '', '', 0, 1);
-	print load_fiche_titre($title, $linktotasks.'   '.$linktocreatetask, 'projecttask', 0, '', '', $massactionbutton);
+	print load_fiche_titre($title, $linktotasks.'   '.$linktocreatetask, 'projecttask', 0, '', '', (string) ($massactionbutton ?? ''));
 
 	$objecttmp = new Task($db);
 	$trackid = 'task'.$taskstatic->id;