diff --git a/htdocs/product/stats/contrat.php b/htdocs/product/stats/contrat.php
index 870e7f81fda..6712ac33185 100644
--- a/htdocs/product/stats/contrat.php
+++ b/htdocs/product/stats/contrat.php
@@ -179,7 +179,7 @@ if ($id > 0 || !empty($ref)) {
 				$option .= '&search_month='.urlencode($search_month);
 			}
 			if (!empty($search_year)) {
-				$option .= '&search_year='.urlencode($search_year);
+				$option .= '&search_year='.urlencode((string) ($search_year));
 			}
 
 			print '<form method="post" action="'.$_SERVER['PHP_SELF'].'?id='.$product->id.'" name="search_form">'."\n";
@@ -195,7 +195,7 @@ if ($id > 0 || !empty($ref)) {
 			print_barre_liste($langs->trans("Contrats"), $page, $_SERVER["PHP_SELF"], $option, $sortfield, $sortorder, '', $num, $totalofrecords, '', 0, '', '', $limit, 0, 0, 1);
 
 			if (!empty($page)) {
-				$option .= '&page='.urlencode($page);
+				$option .= '&page='.urlencode((string) ($page));
 			}
 
 			$i = 0;