diff --git a/coverage/fuel3.html b/coverage/fuel3.html
index a9e7eb9..86e0424 100644
--- a/coverage/fuel3.html
+++ b/coverage/fuel3.html
@@ -96,9 +96,9 @@
 <script type="text/javascript">
     const ort = new ol.layer.Tile({
         source: new ol.source.OSM({
-            "url": "http://tiles.wmflabs.org/bw-mapnik/{z}/{x}/{y}.png"
+            "url" : "http://tiles.wmflabs.org/bw-mapnik/" + "{z}/{x}/{y}.png"
         }),
-        title: "OpenStreetMap std",
+        title: "OpenStreetMap gray",
         visible: true
     });