diff --git a/addons/stock/models/stock_picking.py b/addons/stock/models/stock_picking.py
index be4f7f45b17..8bf0a056dec 100644
--- a/addons/stock/models/stock_picking.py
+++ b/addons/stock/models/stock_picking.py
@@ -640,6 +640,10 @@ class Picking(models.Model):
         if vals.get('partner_id'):
             for picking in res.filtered(lambda p: p.location_id.usage == 'supplier' or p.location_dest_id.usage == 'customer'):
                 picking.message_subscribe([vals.get('partner_id')])
+        if vals.get('picking_type_id'):
+            for move in res.move_lines:
+                if not move.description_picking:
+                    move.description_picking = move.product_id._get_description(move.picking_id.picking_type_id)
 
         return res
 
@@ -667,6 +671,7 @@ class Picking(models.Model):
             self.mapped('move_lines').filtered(lambda move: not move.scrapped).write(after_vals)
         if vals.get('move_lines'):
             self._autoconfirm_picking()
+
         return res
 
     def unlink(self):
diff --git a/addons/stock/tests/test_move2.py b/addons/stock/tests/test_move2.py
index 54be08e6d91..6ba16035914 100644
--- a/addons/stock/tests/test_move2.py
+++ b/addons/stock/tests/test_move2.py
@@ -5,8 +5,8 @@ from datetime import timedelta
 
 from odoo.addons.stock.tests.common import TestStockCommon
 from odoo.exceptions import UserError
-from odoo.tests import Form
 
+from odoo.tests.common import Form
 
 class TestPickShip(TestStockCommon):
     def create_pick_ship(self):
@@ -2829,3 +2829,27 @@ class TestAutoAssign(TestStockCommon):
         move.lot_ids = [(4, lot2.id)]
         move.lot_ids = [(4, lot3.id)]
         self.assertEqual(move.quantity_done, 3.0/12.0)
+
+    def test_update_description(self):
+        """ Create an empty picking. Adds a move on product1, select the picking type, add
+        again a move on product1. Confirm the picking. The two stock moves should be merged. """
+        product1 = self.env['product.product'].create({
+            'name': 'product',
+            'type':'product',
+        })
+        picking_form = Form(self.env['stock.picking'])
+        with picking_form.move_ids_without_package.new() as move:
+            move.product_id = product1
+            move.product_uom_qty = 10
+            move.location_id = self.env.ref('stock.stock_location_suppliers')
+            move.location_dest_id = self.env.ref('stock.stock_location_stock')
+        picking_form.picking_type_id = self.env.ref('stock.picking_type_in')
+        with picking_form.move_ids_without_package.new() as move:
+            move.product_id = product1
+            move.product_uom_qty = 15
+
+        picking = picking_form.save()
+        picking.action_confirm()
+
+        self.assertEqual(len(picking.move_lines), 1)
+        self.assertEqual(picking.move_lines.product_uom_qty, 25)