diff --git a/ckanext/xloader/utils.py b/ckanext/xloader/utils.py
index ec8e4bbd..e504a738 100644
--- a/ckanext/xloader/utils.py
+++ b/ckanext/xloader/utils.py
@@ -83,6 +83,7 @@ def set_resource_metadata(update_dict):
     # better fix
 
     q = model.Session.query(model.Resource). \
+        with_for_update(of=model.Resource). \
         filter(model.Resource.id == update_dict['resource_id'])
     resource = q.one()