diff --git a/umap/static/umap/js/modules/caption.js b/umap/static/umap/js/modules/caption.js
index 3374eabc..9ebe01ce 100644
--- a/umap/static/umap/js/modules/caption.js
+++ b/umap/static/umap/js/modules/caption.js
@@ -31,7 +31,7 @@ export default class Caption {
     const p = DomUtil.create('p', 'datalayer-legend', container),
       legend = DomUtil.create('span', '', p),
       headline = DomUtil.create('strong', '', p)
-    datalayer.onceLoaded(function () {
+    datalayer.onceLoaded(() => {
       datalayer.renderLegend(legend)
       if (datalayer.options.description) {
         DomUtil.element({
@@ -89,8 +89,8 @@ export default class Caption {
     const urls = {
       leaflet: 'http://leafletjs.com',
       django: 'https://www.djangoproject.com',
-      umap: 'http://wiki.openstreetmap.org/wiki/UMap',
-      changelog: 'https://umap-project.readthedocs.io/en/master/changelog/',
+      umap: 'https://umap-project.org/',
+      changelog: 'https://docs.umap-project.org/en/master/changelog/',
       version: this.map.options.umap_version,
     }
     const creditHTML = translate(
diff --git a/umap/static/umap/js/umap.js b/umap/static/umap/js/umap.js
index e99d346e..8bc9ac21 100644
--- a/umap/static/umap/js/umap.js
+++ b/umap/static/umap/js/umap.js
@@ -912,15 +912,11 @@ U.Map = L.Map.extend({
   },
 
   openBrowser: function (mode) {
-    this.onceDatalayersLoaded(function () {
-      this.browser.open(mode)
-    })
+    this.onceDatalayersLoaded(() => this.browser.open(mode))
   },
 
   openCaption: function () {
-    this.onceDatalayersLoaded(function () {
-      this.caption.open()
-    })
+    this.onceDatalayersLoaded(() => this.caption.open())
   },
 
   eachDataLayer: function (method, context) {