diff --git a/addons/sale/tests/test_sale_report.py b/addons/sale/tests/test_sale_report.py
index e02c1860946..3792b759ac6 100644
--- a/addons/sale/tests/test_sale_report.py
+++ b/addons/sale/tests/test_sale_report.py
@@ -21,6 +21,9 @@ class TestSaleReportCurrencyRate(SaleCommon):
         cls.eur_cmp = cls.env['res.company'].create({
             'name': 'EUR Company', 'currency_id': cls.env.ref('base.EUR').id,
         })
+        # The test requires the main company to be in USD so that the currency of the products
+        # shared between companies is USD
+        cls._use_currency('USD')
 
     def test_sale_report_foreign_currency(self):
         """
diff --git a/odoo/addons/base/tests/common.py b/odoo/addons/base/tests/common.py
index 97c8b1f4f00..c2c7b6ea409 100644
--- a/odoo/addons/base/tests/common.py
+++ b/odoo/addons/base/tests/common.py
@@ -40,6 +40,16 @@ class BaseCommon(TransactionCase):
         currency.action_unarchive()
         return currency
 
+    @classmethod
+    def _use_currency(cls, currency_code):
+        # Enforce constant currency
+        currency = cls._enable_currency(currency_code)
+        if not cls.env.company.currency_id == currency:
+            cls.env.transaction.cache.set(cls.env.company, type(cls.env.company).currency_id, currency.id, dirty=True)
+            # this is equivalent to cls.env.company.currency_id = currency but without triggering buisness code checks.
+            # The value is added in cache, and the cache value is set as dirty so that that
+            # the value will be written to the database on next flush.
+            # this was needed because some journal entries may exist when running tests, especially l10n demo data.
 
 class BaseUsersCommon(BaseCommon):