diff --git a/osm-liberty.json b/osm-liberty.json
index cbbf389..49dd0d1 100644
--- a/osm-liberty.json
+++ b/osm-liberty.json
@@ -75,7 +75,7 @@
       "maxzoom": 6,
       "tileSize": 256,
       "tiles": [
-        "http://naturalearthtiles.org/tiles/natural_earth_2_shaded_relief.raster/{z}/{x}/{y}.webp"
+        "http://naturalearthtiles.org/tiles/natural_earth_2_shaded_relief.raster/{z}/{x}/{y}.png"
       ],
       "type": "raster"
     },