diff --git a/addons/bus/static/src/services/bus_service.js b/addons/bus/static/src/services/bus_service.js
index 537e599587f..330949f6a4e 100644
--- a/addons/bus/static/src/services/bus_service.js
+++ b/addons/bus/static/src/services/bus_service.js
@@ -6,6 +6,7 @@ import { registry } from '@web/core/registry';
 import { session } from '@web/session';
 import { isIosApp } from '@web/core/browser/feature_detection';
 import { WORKER_VERSION } from "@bus/workers/websocket_worker";
+import legacySession from "web.session";
 
 const { EventBus } = owl;
 
@@ -29,8 +30,17 @@ export const busService = {
             multiTab.removeSharedValue('last_notification_id');
         }
         const bus = new EventBus();
+        let workerURL = `${legacySession.prefix}/bus/websocket_worker_bundle?v=${WORKER_VERSION}`;
+        if (legacySession.prefix !== window.origin) {
+            // Bus service is loaded from a different origin than the bundle
+            // URL. The Worker expects an URL from this origin, give it a base64
+            // URL that will then load the bundle via "importScripts" which
+            // allows cross origin.
+            const source = `importScripts("${workerURL}");`;
+            workerURL = 'data:application/javascript;base64,' + window.btoa(source);
+        }
         const workerClass = 'SharedWorker' in window && !isIosApp() ? browser.SharedWorker : browser.Worker;
-        const worker = new workerClass(`/bus/websocket_worker_bundle?v=${WORKER_VERSION}`, {
+        const worker = new workerClass(workerURL, {
             name: 'SharedWorker' in window && !isIosApp() ? 'odoo:websocket_shared_worker' : 'odoo:websocket_worker',
         });
         const connectionInitializedDeferred = new Deferred();
@@ -95,6 +105,7 @@ export const busService = {
                 uid = false;
             }
             send('initialize_connection', {
+                websocketURL: `${legacySession.prefix.replace("http", "ws")}/websocket`,
                 debug: odoo.debug,
                 lastNotificationId: multiTab.getSharedValue('last_notification_id', 0),
                 uid,
diff --git a/addons/bus/static/src/workers/websocket_worker.js b/addons/bus/static/src/workers/websocket_worker.js
index d19b0f99f88..a2a3437f545 100644
--- a/addons/bus/static/src/workers/websocket_worker.js
+++ b/addons/bus/static/src/workers/websocket_worker.js
@@ -34,7 +34,7 @@ export const WEBSOCKET_CLOSE_CODES = Object.freeze({
 });
 // Should be incremented on every worker update in order to force
 // update of the worker in browser cache.
-export const WORKER_VERSION = "1.0.0";
+export const WORKER_VERSION = "1.0.1";
 
 /**
  * This class regroups the logic necessary in order for the
@@ -44,8 +44,8 @@ export const WORKER_VERSION = "1.0.0";
  * for SharedWorker and this class implements it.
  */
 export class WebsocketWorker {
-    constructor(websocketURL) {
-        this.websocketURL = websocketURL;
+    constructor() {
+        this.websocketURL = "";
         this.currentUID = null;
         this.isWaitingForNewUID = true;
         this.channelsByClient = new Map();
@@ -200,12 +200,14 @@ export class WebsocketWorker {
      * given client.
      * @param {Number} [param0.lastNotificationId] Last notification id
      * known by the client.
+     * @param {String} [param0.websocketURL] URL of the websocket endpoint.
      * @param {Number|false|undefined} [param0.uid] Current user id
      *     - Number: user is logged whether on the frontend/backend.
      *     - false: user is not logged.
      *     - undefined: not available (e.g. livechat support page)
      */
-    _initializeConnection(client, { debug, lastNotificationId, uid }) {
+    _initializeConnection(client, { debug, lastNotificationId, uid, websocketURL }) {
+        this.websocketURL = websocketURL;
         this.lastNotificationId = lastNotificationId;
         this.debugModeByClient[client] = debug;
         this.isDebug = Object.values(this.debugModeByClient).some(debugValue => debugValue !== '');
diff --git a/addons/bus/static/src/workers/websocket_worker_script.js b/addons/bus/static/src/workers/websocket_worker_script.js
index 58076b78972..be57f7fa087 100644
--- a/addons/bus/static/src/workers/websocket_worker_script.js
+++ b/addons/bus/static/src/workers/websocket_worker_script.js
@@ -5,9 +5,7 @@
 import { WebsocketWorker } from "./websocket_worker";
 
 (function () {
-    const websocketWorker = new WebsocketWorker(
-        `${self.location.protocol === 'https:' ? 'wss' : 'ws'}://${self.location.host}/websocket`
-    );
+    const websocketWorker = new WebsocketWorker();
 
     if (self.name.includes('shared')) {
         // The script is running in a shared worker: let's register every
diff --git a/addons/bus/static/tests/bus_tests.js b/addons/bus/static/tests/bus_tests.js
index 668d6bf5e72..7fd90282c83 100644
--- a/addons/bus/static/tests/bus_tests.js
+++ b/addons/bus/static/tests/bus_tests.js
@@ -13,6 +13,7 @@ const { registry } = require("@web/core/registry");
 const { session } = require('@web/session');
 const { makeDeferred, nextTick, patchWithCleanup } = require("@web/../tests/helpers/utils");
 const { makeTestEnv } = require('@web/../tests/helpers/mock_env');
+const legacySession = require('web.session');
 
 QUnit.module('Bus', {
     beforeEach: function () {
@@ -461,6 +462,26 @@ QUnit.module('Bus', {
             'connect',
         ]);
     });
+
+    QUnit.test("WebSocket connects with URL corresponding to session prefix", async function (assert) {
+        patchWebsocketWorkerWithCleanup();
+        const origin = "http://random-website.com";
+        patchWithCleanup(legacySession, {
+            prefix: origin,
+        });
+        const websocketCreatedDeferred = makeDeferred();
+        patchWithCleanup(window, {
+            WebSocket: function (url) {
+                assert.step(url);
+                websocketCreatedDeferred.resolve();
+                return new EventTarget();
+            },
+        }, { pure: true });
+        const env = await makeTestEnv();
+        env.services["bus_service"].start();
+        await websocketCreatedDeferred;
+        assert.verifySteps([`${origin.replace("http", "ws")}/websocket`]);
+    });
 });
 });
 
diff --git a/addons/bus/static/tests/helpers/mock_websocket.js b/addons/bus/static/tests/helpers/mock_websocket.js
index 6cf13f92154..23730eed884 100644
--- a/addons/bus/static/tests/helpers/mock_websocket.js
+++ b/addons/bus/static/tests/helpers/mock_websocket.js
@@ -6,10 +6,9 @@ import { patchWithCleanup } from "@web/../tests/helpers/utils";
 import { registerCleanup } from "@web/../tests/helpers/cleanup";
 
 class WebSocketMock extends EventTarget {
-    constructor(url) {
+    constructor() {
         super();
         this.readyState = 0;
-        this.url = url;
 
         queueMicrotask(() => {
             this.readyState = 1;
@@ -71,7 +70,7 @@ export function patchWebsocketWorkerWithCleanup(params = {}) {
         },
     }, { pure: true });
     patchWithCleanup(websocketWorker || WebsocketWorker.prototype, params);
-    websocketWorker = websocketWorker || new WebsocketWorker('wss://odoo.com/websocket');
+    websocketWorker = websocketWorker || new WebsocketWorker();
     patchWithCleanup(browser, {
         SharedWorker: function () {
             const sharedWorker = new SharedWorkerMock(websocketWorker);