diff --git a/addons/spreadsheet/models/res_lang.py b/addons/spreadsheet/models/res_lang.py
index 6d4ae813de4..52f0bd46300 100644
--- a/addons/spreadsheet/models/res_lang.py
+++ b/addons/spreadsheet/models/res_lang.py
@@ -20,7 +20,7 @@ class Lang(models.Model):
         return spreadsheet_locales
 
     @api.model
-    def get_user_spreadsheet_locale(self):
+    def _get_user_spreadsheet_locale(self):
         """Convert the odoo lang to a spreadsheet locale."""
         lang = self._lang_get(self.env.user.lang)
         return lang._odoo_lang_to_spreadsheet_locale()
diff --git a/addons/spreadsheet/static/tests/utils/mock_server.js b/addons/spreadsheet/static/tests/utils/mock_server.js
index 4d6d1a4cc71..dab51c1f3ce 100644
--- a/addons/spreadsheet/static/tests/utils/mock_server.js
+++ b/addons/spreadsheet/static/tests/utils/mock_server.js
@@ -1,7 +1,6 @@
 /** @odoo-module */
 
 import { registry } from "@web/core/registry";
-import { constants } from "@odoo/o-spreadsheet";
 
 registry
     .category("mock_server")
@@ -29,7 +28,4 @@ registry
             position: "after",
             decimalPlaces: 2,
         };
-    })
-    .add("res.lang/get_user_spreadsheet_locale", function (route, args) {
-        return constants.DEFAULT_LOCALE;
     });