diff --git a/lib/map.js b/lib/map.js
index bc14cff..4139964 100644
--- a/lib/map.js
+++ b/lib/map.js
@@ -63,7 +63,7 @@ define(['map/clientlayer', 'map/labellayer', 'map/button', 'leaflet', 'map/activ
       var layers = config.mapLayers.map(function (d) {
         return {
           'name': d.name,
-          'layer': L.tileLayer(d.url, d.config)
+          'layer': L.tileLayer(d.url.replace('{format}', document.createElement('canvas').toDataURL('image/webp').indexOf('data:image/webp') === 0 ? 'webp' : 'png'), d.config)
         };
       });