diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index 5acfab70974..360043ab1a4 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -441,10 +441,13 @@ class PurchaseOrder(models.Model):
 
     @api.multi
     def action_set_date_planned(self):
+        # implementation for 9.0 where PO date_planned is not stored
+        date_planned = self.env.context.get('date_planned')
+        if not date_planned:
+            return
         for order in self:
-            #DO NOT FORWARD PORT
             for line in order.order_line:
-                line.update({'date_planned': order.date_planned})
+                line.update({'date_planned': date_planned})
 
 
 class PurchaseOrderLine(models.Model):
diff --git a/addons/purchase/purchase_view.xml b/addons/purchase/purchase_view.xml
index 020c753d479..b51515880e2 100644
--- a/addons/purchase/purchase_view.xml
+++ b/addons/purchase/purchase_view.xml
@@ -252,7 +252,7 @@
                                     <label for="date_planned"/>
                                     <div>
                                         <field name="date_planned" required="1" attrs="{'readonly': [('state', 'not in', ('draft', 'sent'))]}"/>
-                                        <button name="action_set_date_planned" type="object"
+                                        <button name="action_set_date_planned" context="{'date_planned': date_planned}" type="object"
                                             states="draft,sent"
                                             string="Set date to all order lines"
                                             help="This changes the scheduled date of all order lines to the given date"