diff --git a/swh/model/fields/simple.py b/swh/model/fields/simple.py
index f1bff95b8689cafbe311af6c93ddaaa39f08e46e..d85028533ac931a83855bf391270a6614becfe3f 100644
--- a/swh/model/fields/simple.py
+++ b/swh/model/fields/simple.py
@@ -1,3 +1,7 @@
+# Copyright (C) 2015  The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
 
 import datetime
 import numbers