diff --git a/intrastat_product/models/intrastat_product_declaration.py b/intrastat_product/models/intrastat_product_declaration.py
index 4b404b4..d490f5d 100644
--- a/intrastat_product/models/intrastat_product_declaration.py
+++ b/intrastat_product/models/intrastat_product_declaration.py
@@ -424,16 +424,6 @@ class IntrastatProductDeclaration(models.Model):
 
         return weight, suppl_unit_qty
 
-    def _get_amount(self, inv_line, notedict):
-        invoice = inv_line.move_id
-        amount = invoice.currency_id._convert(
-            inv_line.price_subtotal,
-            self.company_id.currency_id,
-            self.company_id,
-            invoice.date,
-        )
-        return amount
-
     def _get_region(self, inv_line, notedict):
         """
         For supplier invoices/refunds: if the invoice line is linked
@@ -710,7 +700,8 @@ class IntrastatProductDeclaration(models.Model):
                     )
                 total_inv_weight += weight
 
-                amount_company_currency = self._get_amount(inv_line, notedict)
+                sign = invoice.move_type in ("in_invoice", "out_refund") and 1 or -1
+                amount_company_currency = sign * inv_line.balance
                 total_inv_product_cc += amount_company_currency
 
                 if inv_intrastat_line: