--- a/src/pyams_zmi/interfaces/templates/admin-layout.pt	Wed Sep 26 16:56:43 2018 +0200
+++ b/src/pyams_zmi/interfaces/templates/admin-layout.pt	Wed Sep 26 16:57:54 2018 +0200
@@ -31,7 +31,10 @@
 				  tal:define="logo config.logo | nothing"
 				  tal:condition="logo">
 				<a href="/admin">
-					<img tal:attributes="src tales:absolute_url(logo, '++thumb++200x36.png');" />
+					<img tal:define="thumbnails tales:thumbnails(logo);
+									 thumb thumbnails.get_thumbnail('220x50');
+									 src tales:absolute_url(thumb);"
+						 src="${src}?_=${tales:timestamp(thumb)}" />
 				</a>
 			</span>
 		</div>