diff --git a/product.py b/product.py
index db39134..ec9afdb 100644
--- a/product.py
+++ b/product.py
@@ -15,10 +15,11 @@ class Product(metaclass=PoolMeta):
         InvoiceLine = Pool().get('account.invoice.line')
         products = InvoiceLine.search_read([
             ('product', '=', self.id),
-            ('invoice.state', 'in', ['posted', 'paid']),
+            ('invoice.state', 'in', ['posted', 'paid', 'validated']),
             ('invoice.type', '=', 'in'),
-        ], fields_names=['unit_price'], order=[('invoice.invoice_date', 'DESC')], limit=1)
+        ], fields_names=['unit_price'], order=[
+            ('invoice.invoice_date', 'DESC')],
+            limit=1)
         if products:
             res = products[0]['unit_price']
         return res
-