diff --git a/README.txt b/README.txt
index 9061672..61fbd37 100644
--- a/README.txt
+++ b/README.txt
@@ -76,3 +76,7 @@ gadjo/static/images/info-icon.png and icons/*.svg are derived work of icons
 from gnome-icon-theme-symbolic, published under the Creative Commons
 Attribution-Share Alike 3.0 United States License by the GNOME Project, see
 http://www.gnome.org/.
+
+gadjo/static/css/adwaita-lock.jpg is a derived work of adwaita-lock.jpg from
+gnome-backgrounds, copyright © 2011 Jakub Steiner <jimmac@gmail.com>, and
+licensed under Creative Commons Attribution-ShareAlike 3.0 License.