diff --git a/js/background.js b/js/background.js
index 4b4a9f7..3f1e7d4 100644
--- a/js/background.js
+++ b/js/background.js
@@ -1,12 +1,12 @@
+const urls = [
+  "*://*.tile.openstreetmap.org/*"
+]
+
 function replaceTileserver(request) {
   var url = request.url.replace("tile.openstreetmap.org", "tiles.demostat.de");
   console.log("custom-openstreetmap-tile-server: " + request.url + " -> " + url);
   return {redirectUrl: url};
 }
 
-urls = [
-  "*://*.tile.openstreetmap.org/*"
-]
-
 
 chrome.webRequest.onBeforeRequest.addListener(replaceTileserver, {urls: urls}, ["blocking"]);