diff --git a/addons/mrp/models/mrp_production.py b/addons/mrp/models/mrp_production.py
index 09c779b29da..339c97d5bb0 100644
--- a/addons/mrp/models/mrp_production.py
+++ b/addons/mrp/models/mrp_production.py
@@ -509,12 +509,13 @@ class MrpProduction(models.Model):
                 move[0]._recompute_state()
                 move[0]._action_assign()
                 move[0].unit_factor = quantity / move[0].raw_material_production_id.product_qty
-            elif quantity < 0:  # Do not remove 0 lines
+                return move[0], old_qty, quantity
+            else:
                 if move[0].quantity_done > 0:
                     raise UserError(_('Lines need to be deleted, but can not as you still have some quantities to consume in them. '))
                 move[0]._action_cancel()
                 move[0].unlink()
-            return move[0], old_qty, quantity
+                return self.env['stock.move'], old_qty, quantity
         else:
             move = self._generate_raw_move(bom_line, line_data)
             return move, 0, quantity
diff --git a/addons/mrp/tests/test_order.py b/addons/mrp/tests/test_order.py
index 61538b5ecab..fc98bfcdbc3 100644
--- a/addons/mrp/tests/test_order.py
+++ b/addons/mrp/tests/test_order.py
@@ -5,6 +5,7 @@ from odoo.tests import Form
 from datetime import datetime, timedelta
 
 from odoo.fields import Datetime as Dt
+from odoo.exceptions import UserError
 from odoo.addons.mrp.tests.common import TestMrpCommon
 
 
@@ -677,6 +678,51 @@ class TestMrpOrder(TestMrpCommon):
         self.assertEqual(mo.move_raw_ids.filtered(lambda m: m.product_id == p1).quantity_done, 20, 'Update the produce quantity should not impact already produced quantity.')
         mo.button_mark_done()
 
+    def test_product_produce_6(self):
+        """ Plan 5 finished products, reserve and produce 3. Post the current production.
+        Simulate an unlock and edit and, on the opened moves, set the consumed quantity
+        to 3. Now, try to update the quantity to produce to 3. It should fail since there
+        are consumed quantities. Unlock and edit, remove the consumed quantities and
+        update the quantity to produce to 3."""
+        self.stock_location = self.env.ref('stock.stock_location_stock')
+        mo, bom, p_final, p1, p2 = self.generate_mo()
+        self.assertEqual(len(mo), 1, 'MO should have been created')
+
+        self.env['stock.quant']._update_available_quantity(p1, self.stock_location, 20)
+
+        self.env['stock.quant']._update_available_quantity(p2, self.stock_location, 5)
+        mo.action_assign()
+
+        produce_wizard = self.env['mrp.product.produce'].with_context({
+            'active_id': mo.id,
+            'active_ids': [mo.id],
+        }).create({
+            'product_qty': 3.0,
+        })
+        produce_wizard._onchange_product_qty()
+        produce_wizard.do_produce()
+
+        mo.post_inventory()
+        self.assertEqual(len(mo.move_raw_ids), 4)
+
+        mo.move_raw_ids.filtered(lambda m: m.state != 'done')[0].quantity_done = 3
+
+        update_quantity_wizard = self.env['change.production.qty'].create({
+            'mo_id': mo.id,
+            'product_qty': 3,
+        })
+        with self.assertRaises(UserError):
+            update_quantity_wizard.change_prod_qty()
+
+        mo.move_raw_ids.filtered(lambda m: m.state != 'done')[0].quantity_done = 0
+        update_quantity_wizard.change_prod_qty()
+
+        self.assertEqual(len(mo.move_raw_ids), 2)
+
+        mo.button_mark_done()
+        self.assertTrue(all(s == 'done' for s in mo.move_raw_ids.mapped('state')))
+        self.assertEqual(sum(mo.move_raw_ids.mapped('move_line_ids.product_uom_qty')), 0)
+
     def test_product_produce_uom(self):
         plastic_laminate = self.env.ref('mrp.product_product_plastic_laminate')
         bom = self.env.ref('mrp.mrp_bom_plastic_laminate')
diff --git a/addons/mrp/wizard/change_production_qty.py b/addons/mrp/wizard/change_production_qty.py
index b92616c9a50..ff7439f3d12 100644
--- a/addons/mrp/wizard/change_production_qty.py
+++ b/addons/mrp/wizard/change_production_qty.py
@@ -54,15 +54,22 @@ class ChangeProductionQty(models.TransientModel):
             boms, lines = production.bom_id.explode(production.product_id, factor, picking_type=production.bom_id.picking_type_id)
             documents = {}
             for line, line_data in lines:
-                move, old_qty, new_qty = production._update_raw_move(line, line_data)
+                move = production.move_raw_ids.filtered(lambda x: x.bom_line_id.id == line.id and x.state not in ('done', 'cancel'))
+                if move:
+                    old_qty = move[0].product_uom_qty
+                else:
+                    old_qty = 0
                 iterate_key = production._get_document_iterate_key(move)
                 if iterate_key:
-                    document = self.env['stock.picking']._log_activity_get_documents({move: (new_qty, old_qty)}, iterate_key, 'UP')
+                    document = self.env['stock.picking']._log_activity_get_documents({move: (line_data['qty'], old_qty)}, iterate_key, 'UP')
                     for key, value in document.items():
                         if documents.get(key):
                             documents[key] += [value]
                         else:
                             documents[key] = [value]
+
+                production._update_raw_move(line, line_data)
+
             production._log_manufacture_exception(documents)
             operation_bom_qty = {}
             for bom, bom_data in boms: