diff --git a/addons/stock/models/stock_move_line.py b/addons/stock/models/stock_move_line.py
index a63e37929f3..81fda382d91 100644
--- a/addons/stock/models/stock_move_line.py
+++ b/addons/stock/models/stock_move_line.py
@@ -268,7 +268,7 @@ class StockMoveLine(models.Model):
                             except UserError:
                                 pass
                     if new_product_qty != ml.product_qty:
-                        new_product_uom_qty = self.product_id.uom_id._compute_quantity(new_product_qty, self.product_uom_id, rounding_method='HALF-UP')
+                        new_product_uom_qty = ml.product_id.uom_id._compute_quantity(new_product_qty, ml.product_uom_id, rounding_method='HALF-UP')
                         ml.with_context(bypass_reservation_update=True).product_uom_qty = new_product_uom_qty
 
         # When editing a done move line, the reserved availability of a potential chained move is impacted. Take care of running again `_action_assign` on the concerned moves.