diff --git a/product.py b/product.py
index 0ff6d703a0..fbc76892a2 100644
--- a/product.py
+++ b/product.py
@@ -144,21 +144,22 @@ class Product(metaclass=PoolMeta):
         user = User(Transaction().user)
 
         for product in products:
-            prices[product.id] = product._get_sale_unit_price(
-                quantity=quantity)
-            if uom and product.default_uom.category == uom.category:
-                prices[product.id] = Uom.compute_price(
-                    product.default_uom, prices[product.id], uom)
-            else:
-                prices[product.id] = Uom.compute_price(
-                    product.default_uom, prices[product.id], product.sale_uom)
-            if currency and user.company:
+            unit_price = product._get_sale_unit_price(quantity=quantity)
+            if unit_price is not None:
+                if uom and product.default_uom.category == uom.category:
+                    unit_price = Uom.compute_price(
+                        product.default_uom, unit_price, uom)
+                else:
+                    unit_price = Uom.compute_price(
+                        product.default_uom, unit_price, product.sale_uom)
+            if currency and user.company and unit_price is not None:
                 if user.company.currency != currency:
                     date = Transaction().context.get('sale_date') or today
                     with Transaction().set_context(date=date):
-                        prices[product.id] = Currency.compute(
-                            user.company.currency, prices[product.id],
+                        unit_price = Currency.compute(
+                            user.company.currency, unit_price,
                             currency, round=False)
+            prices[product.id] = unit_price
         return prices
 
     @property
diff --git a/sale.py b/sale.py
index 1e34d4b57b..1e8b845d22 100644
--- a/sale.py
+++ b/sale.py
@@ -1310,7 +1310,7 @@ class SaleLine(TaxableMixin, sequence_ordered(), ModelSQL, ModelView):
                 self._get_context_sale_price()):
             unit_price = Product.get_sale_price([self.product],
                 self.quantity or 0)[self.product.id]
-            if unit_price:
+            if unit_price is not None:
                 unit_price = round_price(unit_price)
             return unit_price