diff --git a/htdocs/core/class/commonobject.class.php b/htdocs/core/class/commonobject.class.php
index 7d0a1266579..dbd2a0d4444 100644
--- a/htdocs/core/class/commonobject.class.php
+++ b/htdocs/core/class/commonobject.class.php
@@ -738,11 +738,11 @@ abstract class CommonObject
 		}
 		if ($this->element == 'contact') {
 			$contactid = $this->id;
-			$thirdpartyid = $object->fk_soc;
+			$thirdpartyid = empty($object->fk_soc) ? 0 : $object->fk_soc;
 		}
 		if ($this->element == 'user') {
 			$contactid = $this->contact_id;
-			$thirdpartyid = $object->fk_soc;
+			$thirdpartyid = empty($object->fk_soc) ? 0 : $object->fk_soc;
 		}
 
 		$out = '';