diff --git a/addons/sale/sale_analytic.py b/addons/sale/sale_analytic.py
index 35ca6a9ccb03b7323257d33a6c743f7bc0f15a10..1f814d04ad9a5e2b1d5080e054c7720b0e2a85af 100644
--- a/addons/sale/sale_analytic.py
+++ b/addons/sale/sale_analytic.py
@@ -39,6 +39,8 @@ class AccountAnalyticLine(models.Model):
     so_line = fields.Many2one('sale.order.line', string='Sale Order Line')
 
     def _get_invoice_price(self, order):
+        if self.unit_amount == 0.0:
+            return 0.0
         price_unit = abs(self.amount / self.unit_amount)
         if self.currency_id and self.currency_id != order.currency_id:
             price_unit = self.currency_id.compute(price_unit, order.currency_id)