diff --git a/addons/document_ftp/ftpserver/abstracted_fs.py b/addons/document_ftp/ftpserver/abstracted_fs.py
index 5bb0f674fa2..0766d42d501 100644
--- a/addons/document_ftp/ftpserver/abstracted_fs.py
+++ b/addons/document_ftp/ftpserver/abstracted_fs.py
@@ -319,6 +319,7 @@ class abstracted_fs(object):
     def get_node_cr_uid(self, node):
         """ Get cr, uid, pool from a node
         """
+        assert node
         db = pooler.get_db(node.context.dbname)
         return db.cursor(), node.context.uid