diff --git a/README.md b/README.md
index fecc845..a9e4332 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,8 @@ adapt the behavior to your needs.
 * `PUBLIC_PATH=https://.../foobar` to serve the app from a subdirectory.
 * `API_BASE_URL=https://...` to specify the location of the server (defaults
     to `/`). The value should end with a trailing slash.
+* `TILE_SERVER=` to pass a specific tile server to use rather than the default
+    one.
 
 
 ## Server part
diff --git a/config/prod.env.js b/config/prod.env.js
index 493ebe2..a86e7d4 100644
--- a/config/prod.env.js
+++ b/config/prod.env.js
@@ -2,4 +2,5 @@
 module.exports = {
   NODE_ENV: '"production"',
   API_BASE_URL: JSON.stringify(process.env.API_BASE_URL),
+  TILE_SERVER: JSON.stringify(process.env.TILE_SERVER),
 }
diff --git a/src/components/Map.vue b/src/components/Map.vue
index be1a605..a7f2be5 100644
--- a/src/components/Map.vue
+++ b/src/components/Map.vue
@@ -26,7 +26,7 @@ L.Icon.Default.mergeOptions({
 export const DEFAULT_ZOOM = 17;
 export const MIN_ZOOM = 15;
 export const MAX_ZOOM = 18;
-export const TILE_SERVER = 'http://a.tile.opencyclemap.org/cycle/{z}/{x}/{y}.png';
+export const TILE_SERVER = process.env.TILE_SERVER || 'https://a.tile.thunderforest.com/cycle/{z}/{x}/{y}.png';
 
 
 export default {