diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 76ed140870f..4aa46784ad4 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -6262,10 +6262,10 @@ function getCommonSubstitutionArray($outputlangs, $onlykey = 0, $exclude = null,
 			$substitutionarray['__SUPPLIER_ORDER_DATE_DELIVERY__'] = (isset($object->date_livraison) ? dol_print_date($object->date_livraison, 'day', 0, $outputlangs) : '');
 			$substitutionarray['__SUPPLIER_ORDER_DELAY_DELIVERY__'] = (isset($object->availability_code) ? ($outputlangs->transnoentities("AvailabilityType".$object->availability_code) != ('AvailabilityType'.$object->availability_code) ? $outputlangs->transnoentities("AvailabilityType".$object->availability_code) : $outputlangs->convToOutputCharset(isset($object->availability) ? $object->availability : '')) : '');
 
-			$birthday = dol_print_date($object->birth, 'day');
-
 			if (is_object($object) && ($object->element == 'adherent' || $object->element == 'member') && $object->id > 0)
 			{
+				$birthday = (empty($object->birth) ? '': dol_print_date($object->birth, 'day'));
+
 				$substitutionarray['__MEMBER_ID__'] = (isset($object->id) ? $object->id : '');
 				if (method_exists($object, 'getCivilityLabel')) $substitutionarray['__MEMBER_CIVILITY__'] = $object->getCivilityLabel();
 				$substitutionarray['__MEMBER_FIRSTNAME__'] = (isset($object->firstname) ? $object->firstname : '');