diff --git a/stock_quant_manual_assign/tests/test_stock_quant_manual_assign.py b/stock_quant_manual_assign/tests/test_stock_quant_manual_assign.py
index cbab4dee9..7c4cf3d91 100644
--- a/stock_quant_manual_assign/tests/test_stock_quant_manual_assign.py
+++ b/stock_quant_manual_assign/tests/test_stock_quant_manual_assign.py
@@ -3,6 +3,7 @@
 # License AGPL-3 - See http://www.gnu.org/licenses/agpl-3.0.html
 
 import openerp.tests.common as common
+from openerp import exceptions
 
 
 class TestStockQuantManualAssign(common.TransactionCase):
@@ -65,6 +66,21 @@ class TestStockQuantManualAssign(common.TransactionCase):
                 self.assertFalse(line.selected)
         self.assertEqual(wizard.move_qty, self.move.product_uom_qty)
 
+    def test_quant_assign_wizard_constraint(self):
+        wizard = self.quant_assign_wizard.with_context(
+            active_id=self.move.id).create({
+                'name': 'New wizard',
+            })
+        self.assertEqual(len(wizard.quants_lines.ids), 3,
+                         'Three quants created, three quants got by default')
+        self.assertEqual(len(wizard.quants_lines.filtered('selected').ids), 0,
+                         'None of the quants must have been selected')
+        self.assertEqual(wizard.lines_qty, 0.0,
+                         'None selected must give 0')
+        with self.assertRaises(exceptions.ValidationError):
+            wizard.write({'quants_lines': [(1, wizard.quants_lines[:1].id,
+                                            {'selected': True, 'qty': 500})]})
+
     def test_quant_manual_assign(self):
         wizard = self.quant_assign_wizard.with_context(
             active_id=self.move.id).create({
@@ -74,14 +90,24 @@ class TestStockQuantManualAssign(common.TransactionCase):
                          'Three quants created, three quants got by default')
         wizard.quants_lines[0].write({
             'selected': True,
-            'qty': 100.0,
         })
+        wizard.quants_lines[0].onchange_selected()
         wizard.quants_lines[1].write({
             'selected': True,
             'qty': 50.0,
         })
         self.assertEqual(wizard.lines_qty, 150.0)
         self.assertEqual(wizard.move_qty, 250.0)
+        wizard.assign_quants()
+        self.assertEqual(len(wizard.quants_lines.filtered('selected')),
+                         len(self.move.reserved_quant_ids))
+        selected_quants = wizard.quants_lines.filtered(
+            'selected').mapped('quant')
+        self.assertEqual(
+            sum(self.move.reserved_quant_ids.mapped('qty')),
+            wizard.lines_qty)
+        for quant in self.move.reserved_quant_ids:
+            self.assertTrue(quant in selected_quants)
 
     def test_quant_assign_wizard_after_availability_check(self):
         self.move.action_assign()