diff --git a/addons/web/controllers/utils.py b/addons/web/controllers/utils.py
index cf625a623c9..18d6f5e0d90 100644
--- a/addons/web/controllers/utils.py
+++ b/addons/web/controllers/utils.py
@@ -101,7 +101,7 @@ def ensure_db(redirect='/web/database/selector'):
     # always switch the session to the computed db
     if db != request.session.db:
         request.session = http.root.session_store.new()
-        request.session.update(http.DEFAULT_SESSION, db=db)
+        request.session.update(http.get_default_session(), db=db)
         request.session.context['lang'] = request.default_lang()
         werkzeug.exceptions.abort(request.redirect(request.httprequest.url, 302))
 
diff --git a/addons/web/tests/test_login.py b/addons/web/tests/test_login.py
index be6a863f4b0..e811c48d007 100644
--- a/addons/web/tests/test_login.py
+++ b/addons/web/tests/test_login.py
@@ -12,7 +12,7 @@ class TestWebLoginCommon(HttpCase):
     def login(self, username, password):
         """Log in with provided credentials and return response to POST request or raises for status."""
         self.session = http.root.session_store.new()
-        self.session.update(http.DEFAULT_SESSION, db=get_db_name())
+        self.session.update(http.get_default_session(), db=get_db_name())
         self.opener = Opener(self.env.cr)
         self.opener.cookies.set('session_id', self.session.sid, domain=HOST, path='/')
 
diff --git a/addons/website/tools.py b/addons/website/tools.py
index 58109d9c24a..ac46d46a49a 100644
--- a/addons/website/tools.py
+++ b/addons/website/tools.py
@@ -46,7 +46,7 @@ def MockRequest(
         params={},
         redirect=env['ir.http']._redirect,
         session=DotDict(
-            odoo.http.DEFAULT_SESSION,
+            odoo.http.get_default_session(),
             geoip={'country_code': country_code},
             sale_order_id=sale_order_id,
             website_sale_current_pl=website_sale_current_pl,
diff --git a/odoo/http.py b/odoo/http.py
index e9cc901aaba..c40d69e9e6c 100644
--- a/odoo/http.py
+++ b/odoo/http.py
@@ -208,20 +208,19 @@ CSRF_TOKEN_SALT = 60 * 60 * 24 * 365
 DEFAULT_LANG = 'en_US'
 
 # The dictionnary to initialise a new session with.
-DEFAULT_SESSION = {
-    'context': {
-        #'lang': request.default_lang()  # must be set at runtime
-    },
-    'db': None,
-    'debug': '',
-    'login': None,
-    'uid': None,
-    'session_token': None,
-    # profiling
-    'profile_session': None,
-    'profile_collectors': None,
-    'profile_params': None,
-}
+def get_default_session():
+    return {
+        'context': {},  # 'lang': request.default_lang()  # must be set at runtime
+        'db': None,
+        'debug': '',
+        'login': None,
+        'uid': None,
+        'session_token': None,
+        # profiling
+        'profile_session': None,
+        'profile_collectors': None,
+        'profile_params': None,
+    }
 
 # The request mimetypes that transport JSON in their body.
 JSON_MIMETYPES = ('application/json', 'application/json-rpc')
@@ -957,10 +956,10 @@ class Session(collections.abc.MutableMapping):
         })
 
     def logout(self, keep_db=False):
-        db = self.db if keep_db else DEFAULT_SESSION['db']  # None
+        db = self.db if keep_db else get_default_session()['db']  # None
         debug = self.debug
         self.clear()
-        self.update(DEFAULT_SESSION, db=db, debug=debug)
+        self.update(get_default_session(), db=db, debug=debug)
         self.context['lang'] = request.default_lang() if request else DEFAULT_LANG
         self.should_rotate = True
 
@@ -1115,7 +1114,7 @@ class Request:
             session.sid = sid  # in case the session was not persisted
         session.is_explicit = is_explicit
 
-        for key, val in DEFAULT_SESSION.items():
+        for key, val in get_default_session().items():
             session.setdefault(key, val)
         if not session.context.get('lang'):
             session.context['lang'] = self.default_lang()
@@ -1258,7 +1257,7 @@ class Request:
         return consteq(hm, hm_expected)
 
     def default_context(self):
-        return dict(DEFAULT_SESSION['context'], lang=self.default_lang())
+        return dict(get_default_session()['context'], lang=self.default_lang())
 
     def default_lang(self):
         """Returns default user language according to request specification
diff --git a/odoo/tests/common.py b/odoo/tests/common.py
index 5cf12570983..58ef4a315ea 100644
--- a/odoo/tests/common.py
+++ b/odoo/tests/common.py
@@ -1726,7 +1726,7 @@ class HttpCase(TransactionCase):
             odoo.http.root.session_store.delete(self.session)
 
         self.session = session = odoo.http.root.session_store.new()
-        session.update(odoo.http.DEFAULT_SESSION, db=get_db_name())
+        session.update(odoo.http.get_default_session(), db=get_db_name())
         session.context['lang'] = odoo.http.DEFAULT_LANG
 
         if user: # if authenticated