diff --git a/addons/purchase_stock/models/account_invoice.py b/addons/purchase_stock/models/account_invoice.py
index 10d59919286..a64176b4b8d 100644
--- a/addons/purchase_stock/models/account_invoice.py
+++ b/addons/purchase_stock/models/account_invoice.py
@@ -100,19 +100,16 @@ class AccountMove(models.Model):
 
                 price_unit = line.price_unit * (1 - (line.discount or 0.0) / 100.0)
                 if line.tax_ids:
-                    if line.discount and line.quantity:
-                        # We do not want to round the price unit since :
-                        # - It does not follow the currency precision
-                        # - It may include a discount
-                        # Since compute_all still rounds the total, we use an ugly workaround:
-                        # multiply then divide the price unit.
-                        price_unit *= line.quantity
-                        price_unit = line.tax_ids.with_context(round=False, force_sign=move._get_tax_force_sign()).compute_all(
-                            price_unit, currency=move.currency_id, quantity=1.0, is_refund=move.move_type == 'in_refund')['total_excluded']
-                        price_unit /= line.quantity
-                    else:
-                        price_unit = line.tax_ids.compute_all(
-                            price_unit, currency=move.currency_id, quantity=1.0, is_refund=move.move_type == 'in_refund')['total_excluded']
+                    # We do not want to round the price unit since :
+                    # - It does not follow the currency precision
+                    # - It may include a discount
+                    # Since compute_all still rounds the total, we use an ugly workaround:
+                    # shift the decimal part using a fixed quantity to avoid rounding issues
+                    prec = 1e+6
+                    price_unit *= prec
+                    price_unit = line.tax_ids.with_context(round=False, force_sign=move._get_tax_force_sign()).compute_all(
+                        price_unit, currency=move.currency_id, quantity=1.0, is_refund=move.move_type == 'in_refund')['total_excluded']
+                    price_unit /= prec
 
                 price_unit_val_dif = price_unit - valuation_price_unit
                 price_subtotal = line.quantity * price_unit_val_dif
diff --git a/addons/purchase_stock/tests/test_stockvaluation.py b/addons/purchase_stock/tests/test_stockvaluation.py
index 799ab741855..83b7e43725b 100644
--- a/addons/purchase_stock/tests/test_stockvaluation.py
+++ b/addons/purchase_stock/tests/test_stockvaluation.py
@@ -1299,3 +1299,30 @@ class TestStockValuationWithCOA(AccountTestInvoicingCommon):
         # Check if something was posted in the price difference account
         price_diff_aml = invoice.line_ids.filtered(lambda l: l.account_id == self.price_diff_account)
         self.assertEqual(len(price_diff_aml), 0, "No line should have been generated in the price difference account.")
+
+    def test_anglosaxon_valuation_price_unit_diff_standard(self):
+        """
+        Check the price unit difference account is hit with the correct amount
+        """
+        self.env.ref("product.decimal_price").digits = 6
+        self.env.company.anglo_saxon_accounting = True
+        self.product1.categ_id.property_cost_method = 'standard'
+        self.product1.categ_id.property_valuation = 'real_time'
+        self.product1.categ_id.property_account_creditor_price_difference_categ = self.price_diff_account
+        self.product1.standard_price = 0.01719
+
+        invoice = self.env['account.move'].create({
+            'move_type': 'in_invoice',
+            'invoice_date': '2022-03-31',
+            'partner_id': self.partner_id.id,
+            'invoice_line_ids': [
+                (0, 0, {'product_id': self.product1.id, 'quantity': 30000, 'price_unit': 0.01782, 'tax_ids': self.tax_purchase_a.ids})
+            ]
+        })
+
+        invoice.action_post()
+
+        # Check if something was posted in the price difference account
+        price_diff_aml = invoice.line_ids.filtered(lambda l: l.account_id == self.price_diff_account)
+        self.assertEqual(len(price_diff_aml), 1, "A line should have been generated in the price difference account.")
+        self.assertAlmostEqual(price_diff_aml.balance, 18.90)