diff --git a/umap/static/umap/js/modules/sync/engine.js b/umap/static/umap/js/modules/sync/engine.js
index 9c4f15e6..7de5f662 100644
--- a/umap/static/umap/js/modules/sync/engine.js
+++ b/umap/static/umap/js/modules/sync/engine.js
@@ -5,7 +5,6 @@ export class SyncEngine {
   constructor(map) {
     this.map = map
     this.receiver = new MessagesDispatcher(this.map)
-
     this._initialize()
   }
   _initialize() {
@@ -15,6 +14,13 @@ export class SyncEngine {
     this.upsert = this.update = this.delete = noop
   }
 
+  async authenticate(tokenURI, webSocketURI, server) {
+    const [response, _, error] = await server.get(tokenURI)
+    if (!error) {
+      this.start(webSocketURI, response.token)
+    }
+  }
+
   start(webSocketURI, authToken) {
     this.transport = new WebSocketTransport(webSocketURI, authToken, this.receiver)
     this.sender = new MessagesSender(this.transport)
diff --git a/umap/static/umap/js/umap.js b/umap/static/umap/js/umap.js
index cd4845c6..66b2539c 100644
--- a/umap/static/umap/js/umap.js
+++ b/umap/static/umap/js/umap.js
@@ -260,22 +260,13 @@ U.Map = L.Map.extend({
 
   initSyncEngine: async function () {
     if (this.options.websocketEnabled == false) return
-    console.log('this.options.syncEnabled', this.options.syncEnabled)
     if (this.options.syncEnabled != true) {
       this.sync.stop()
     } else {
-      // FIXME: Do this directly in the sync engine, which should check if the engine
-      // is already started or not.
-
-      // Get the authentication token from the server
-      // And pass it to the sync engine.
-      // FIXME: use `this.urls`
-      const [response, _, error] = await this.server.get(
-        `/map/${this.options.umap_id}/ws-token/`
-      )
-      if (!error) {
-        this.sync.start(this.options.websocketURI, response.token)
-      }
+      const ws_token_uri = this.urls.get('map_websocket_auth_token', {
+        map_id: this.options.umap_id,
+      })
+      await this.sync.authenticate(ws_token_uri, this.options.websocketURI, this.server)
     }
   },