diff --git a/leaflet-providers.js b/leaflet-providers.js
index ba52511b..bdc66832 100644
--- a/leaflet-providers.js
+++ b/leaflet-providers.js
@@ -202,9 +202,9 @@
 			}
 		},
 		OpenMapSurfer: {
-			url: 'https://korona.geog.uni-heidelberg.de/tiles/{variant}/x={x}&y={y}&z={z}',
+			url: 'https://maps.heigit.org/openmapsurfer/tiles/{variant}/webmercator/{z}/{x}/{y}.png',
 			options: {
-				maxZoom: 20,
+				maxZoom: 19,
 				variant: 'roads',
 				attribution: 'Imagery from <a href="http://giscience.uni-hd.de/">GIScience Research Group @ University of Heidelberg</a> &mdash; Map data {attribution.OpenStreetMap}'
 			},
@@ -213,13 +213,7 @@
 				AdminBounds: {
 					options: {
 						variant: 'adminb',
-						maxZoom: 19
-					}
-				},
-				Grayscale: {
-					options: {
-						variant: 'roadsg',
-						maxZoom: 19
+						maxZoom: 18
 					}
 				}
 			}