diff --git a/addons/mrp_account/models/mrp_production.py b/addons/mrp_account/models/mrp_production.py
index adec951ad40..d66045ab23a 100644
--- a/addons/mrp_account/models/mrp_production.py
+++ b/addons/mrp_account/models/mrp_production.py
@@ -82,7 +82,7 @@ class MrpProduction(models.Model):
             qty_done = finished_move.product_uom._compute_quantity(
                 finished_move.quantity_done, finished_move.product_id.uom_id)
             extra_cost = self.extra_cost * qty_done
-            total_cost = (sum(-m.stock_valuation_layer_ids.value for m in consumed_moves.sudo()) + work_center_cost + extra_cost)
+            total_cost = - sum(consumed_moves.sudo().stock_valuation_layer_ids.mapped('value')) + work_center_cost + extra_cost
             byproduct_moves = self.move_byproduct_ids.filtered(lambda m: m.state not in ('done', 'cancel') and m.quantity_done > 0)
             byproduct_cost_share = 0
             for byproduct in byproduct_moves: