diff --git a/addons/purchase/tests/test_anglo_saxon_valuation_reconciliation.py b/addons/purchase/tests/test_anglo_saxon_valuation_reconciliation.py
index fea9c9e38d0973b24b699a87ed0a124cdd8038c2..6443d2bf9eaa03a10243518f8e643c3c3048498f 100644
--- a/addons/purchase/tests/test_anglo_saxon_valuation_reconciliation.py
+++ b/addons/purchase/tests/test_anglo_saxon_valuation_reconciliation.py
@@ -78,6 +78,19 @@ class TestValuationReconciliation(ValuationReconciliationTestCase):
     def test_invoice_shipment(self):
         """ Tests the case into which we make the invoice first, and then receive the goods.
         """
+        # First, we delete the currency rate defined in demo data for USD on June 6th.
+        # This is mandatory to ensure consistency of the data generated by the test,
+        # as stock pickings created from a PO are by design always created for
+        # the current date (there is no way forcing this), meaning that they
+        # always use today's exchange rate for their valuation.
+        # Despite the fact we rewrite the date of the valuation moves artificially,
+        # we cannot correct the debit and credit values, since the anglosaxon
+        # entries get automatically reconciled (and you cannot modify a reconciled entry).
+        # So, we have to make sure that "today"'s rate will always be the last rate we
+        # created in order to ensure complete control of the test.
+        self.env.ref('base.rateUSDbis').unlink()
+
+
         # Create a PO and an invoice for it
         test_product = self.test_product_order
         purchase_order = self._create_purchase(test_product)