diff --git a/source/layouts/layout.erb b/source/layouts/layout.erb
index 91daf0c..505c572 100644
--- a/source/layouts/layout.erb
+++ b/source/layouts/layout.erb
@@ -18,6 +18,7 @@
         <%= yield %>
 
         <footer class="container-fluid text-center">
+            <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png" /></a><br /><span xmlns:dct="http://purl.org/dc/terms/" href="http://purl.org/dc/dcmitype/InteractiveResource" property="dct:title" rel="dct:type">Building Robots with Rock and Syskit</span> by <a xmlns:cc="http://creativecommons.org/ns#" href="https://github.com/doudou" property="cc:attributionName" rel="cc:attributionURL">Sylvain Joyeux</a> is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>. Copyright Sylvain Joyeux and Contributors
         </footer>
     </body>
 </html>