diff --git a/htdocs/api/class/api.class.php b/htdocs/api/class/api.class.php
index 5918b1a5414..63f66295556 100644
--- a/htdocs/api/class/api.class.php
+++ b/htdocs/api/class/api.class.php
@@ -98,6 +98,7 @@ class DolibarrApi
 
         // Remove $db object property for object
         unset($object->db);
+        unset($object->isextrafieldmanaged);
 		unset($object->ismultientitymanaged);
 		unset($object->restrictiononfksoc);