diff --git a/htdocs/core/class/commonobject.class.php b/htdocs/core/class/commonobject.class.php
index 5b5de36406a..2983282a9e1 100644
--- a/htdocs/core/class/commonobject.class.php
+++ b/htdocs/core/class/commonobject.class.php
@@ -749,7 +749,7 @@ abstract class CommonObject
 			$this->lastname = dol_ucwords(dol_strtolower($this->lastname));
 			$this->firstname = dol_ucwords(dol_strtolower($this->firstname));
 			$this->name = dol_ucwords(dol_strtolower($this->name));
-			$this->name_alias = dol_ucwords(dol_strtolower($this->name_alias));
+			$this->name_alias = isset($this->name_alias)?dol_ucwords(dol_strtolower($this->name_alias)):'';
 		}
 		if (!empty($conf->global->MAIN_ALL_TO_UPPER)) {
 			$this->lastname = dol_strtoupper($this->lastname);