diff --git a/jikimo_purchase_request/wizard/purchase_request_line_make_purchase_order.py b/jikimo_purchase_request/wizard/purchase_request_line_make_purchase_order.py
index 3c997f76..5ce84967 100644
--- a/jikimo_purchase_request/wizard/purchase_request_line_make_purchase_order.py
+++ b/jikimo_purchase_request/wizard/purchase_request_line_make_purchase_order.py
@@ -100,6 +100,22 @@ class PurchaseRequestLineMakePurchaseOrder(models.TransientModel):
     def check_group(self, request_lines):
         # 去掉合并必须同一采购组的限制
         pass
+
+    def _post_process_po_line(self, item, po_line, new_pr_line):
+        self.ensure_one()
+        line = item.line_id
+        # TODO: Check propagate_uom compatibility:
+        new_qty = self.env["purchase.request.line"]._calc_new_qty(
+            line, po_line=po_line, new_pr_line=new_pr_line
+        )
+        po_line.product_qty = new_qty
+        # The quantity update triggers a compute method that alters the
+        # unit price (which is what we want, to honor graduate pricing)
+        # but also the scheduled date which is what we don't want.
+        date_required = line.date_required
+        po_line.date_planned = datetime(
+            date_required.year, date_required.month, date_required.day
+        )
         
 
 class PurchaseRequestLineMakePurchaseOrderItem(models.TransientModel):