diff --git a/htdocs/core/boxes/box_birthdays.php b/htdocs/core/boxes/box_birthdays.php
index 9a2ccd33cf7..d984635bdd6 100644
--- a/htdocs/core/boxes/box_birthdays.php
+++ b/htdocs/core/boxes/box_birthdays.php
@@ -91,7 +91,7 @@ class box_birthdays extends ModeleBoxes
 			$sql .= " WHERE u.entity IN (".getEntity('user').")";
 			$sql .= " AND u.statut = 1";
 			$sql .= dolSqlDateFilter('u.birth', 0, $tmparray['mon'], 0);
-			$sql .= " ORDER BY u.birth ASC";
+			$sql .= " ORDER BY DAYOFMONTH(u.birth) ASC";
 			$sql .= $this->db->plimit($max, 0);
 
 			dol_syslog(get_class($this)."::loadBox", LOG_DEBUG);