diff --git a/developer_manual/app_publishing_maintenance/app_upgrade_guide/upgrade_to_31.rst b/developer_manual/app_publishing_maintenance/app_upgrade_guide/upgrade_to_31.rst
index 816c169a21d..ca622207221 100644
--- a/developer_manual/app_publishing_maintenance/app_upgrade_guide/upgrade_to_31.rst
+++ b/developer_manual/app_publishing_maintenance/app_upgrade_guide/upgrade_to_31.rst
@@ -82,6 +82,8 @@ Removed APIs
 		console.info('Notification action has been executed:', event.notification, event.action)
     })
 
+- Legacy class ``OC_API`` was moved to a private namespace. It should not be needed by applications.
+
 Back-end changes
 ----------------