diff --git a/addons/bus/controllers/websocket.py b/addons/bus/controllers/websocket.py
index d870b3da29c..2056b37d74e 100644
--- a/addons/bus/controllers/websocket.py
+++ b/addons/bus/controllers/websocket.py
@@ -1,7 +1,6 @@
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
 import json
-from werkzeug.exceptions import ServiceUnavailable
 
 from odoo.http import Controller, request, route, SessionExpiredException
 from odoo.addons.base.models.assetsbundle import AssetsBundle
@@ -16,10 +15,6 @@ class WebsocketController(Controller):
         Handle the websocket handshake, upgrade the connection if
         successfull.
         """
-        is_headful_browser = request.httprequest.user_agent and 'Headless' not in request.httprequest.user_agent.string
-        if request.registry.in_test_mode() and is_headful_browser:
-            # Prevent browsers from interfering with the unittests
-            raise ServiceUnavailable()
         return WebsocketConnectionHandler.open_connection(request)
 
     @route('/websocket/health', type='http', auth='none', save_session=False)
diff --git a/addons/bus/static/tests/bus_tests.js b/addons/bus/static/tests/bus_tests.js
index e0f9ddfd5c9..f393996b4cb 100644
--- a/addons/bus/static/tests/bus_tests.js
+++ b/addons/bus/static/tests/bus_tests.js
@@ -358,6 +358,7 @@ QUnit.test("Can reconnect after late close event", async (assert) => {
 
 QUnit.test("Fallback on simple worker when shared worker failed to initialize", async (assert) => {
     addBusServicesToRegistry();
+    patchWebsocketWorkerWithCleanup();
     const originalSharedWorker = browser.SharedWorker;
     const originalWorker = browser.Worker;
     patchWithCleanup(browser, {
diff --git a/addons/bus/tests/common.py b/addons/bus/tests/common.py
index e332c2ec348..7d260983e2d 100644
--- a/addons/bus/tests/common.py
+++ b/addons/bus/tests/common.py
@@ -12,12 +12,12 @@ except ImportError:
     websocket = None
 
 import odoo.tools
-from odoo.tests import HOST, common
+from odoo.tests import HOST, HttpCase
 from ..websocket import CloseCode, Websocket, WebsocketConnectionHandler
 from ..models.bus import dispatch, hashable, channel_with_db
 
 
-class WebsocketCase(common.HttpCase):
+class WebsocketCase(HttpCase):
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
@@ -25,6 +25,8 @@ class WebsocketCase(common.HttpCase):
             cls._logger.warning("websocket-client module is not installed")
             raise unittest.SkipTest("websocket-client module is not installed")
         cls._WEBSOCKET_URL = f"ws://{HOST}:{odoo.tools.config['http_port']}/websocket"
+        websocket_allowed_patch = patch.object(WebsocketConnectionHandler, "websocket_allowed", return_value=True)
+        cls.startClassPatcher(websocket_allowed_patch)
 
     def setUp(self):
         super().setUp()
diff --git a/addons/bus/tests/test_websocket_caryall.py b/addons/bus/tests/test_websocket_caryall.py
index 3e26e661c9d..5c8e70dc7d3 100644
--- a/addons/bus/tests/test_websocket_caryall.py
+++ b/addons/bus/tests/test_websocket_caryall.py
@@ -183,17 +183,6 @@ class TestWebsocketCaryall(WebsocketCase):
         self.assertEqual(notifications[0]['message']['type'], 'notif_type')
         self.assertEqual(notifications[0]['message']['payload'], 'another_message')
 
-    def test_opening_websocket_connection_during_tests(self):
-        # During tests, browsers can't open websocket connections.
-        headers = ['User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.0.0 Safari/537.36']
-        with self.assertRaises(WebSocketBadStatusException) as error_catcher:
-            self.websocket_connect(header=headers)
-        self.assertEqual(error_catcher.exception.status_code, 503)
-
-        # But ChromeHeadless still can.
-        headers = ['User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/102.0.0.0 Safari/537.36']
-        self.websocket_connect()
-
     def test_subscribe_higher_last_notification_id(self):
         server_last_notification_id = self.env['bus.bus'].sudo().search([], limit=1, order='id desc').id or 0
         client_last_notification_id = server_last_notification_id + 1
diff --git a/addons/bus/websocket.py b/addons/bus/websocket.py
index 3d4bd77b46c..d44938c1d93 100644
--- a/addons/bus/websocket.py
+++ b/addons/bus/websocket.py
@@ -19,7 +19,7 @@ from urllib.parse import urlparse
 from weakref import WeakSet
 
 from werkzeug.local import LocalStack
-from werkzeug.exceptions import BadRequest, HTTPException
+from werkzeug.exceptions import BadRequest, HTTPException, ServiceUnavailable
 
 import odoo
 from odoo import api
@@ -821,6 +821,10 @@ class WebsocketConnectionHandler:
         'sec-websocket-version', 'upgrade', 'origin',
     }
 
+    @classmethod
+    def websocket_allowed(cls, request):
+        return not request.registry.in_test_mode()
+
     @classmethod
     def open_connection(cls, request):
         """
@@ -831,6 +835,8 @@ class WebsocketConnectionHandler:
         versions the client supports and those we support.
         :raise: BadRequest if the handshake data is incorrect.
         """
+        if not cls.websocket_allowed(request):
+            raise ServiceUnavailable("Websocket is disabled in test mode")
         cls._handle_public_configuration(request)
         try:
             response = cls._get_handshake_response(request.httprequest.headers)