diff --git a/issue6451002_60001.diff b/issue6451002_60001.diff
new file mode 100644
index 0000000..899d519
--- /dev/null
+++ b/issue6451002_60001.diff
@@ -0,0 +1,68 @@
+Index: trytond/setup.py
+===================================================================
+
+--- a/trytond/setup.py
++++ b/trytond/setup.py
+@@ -91,4 +91,5 @@
+     zip_safe=False,
+     test_suite='trytond.tests',
+     test_loader='trytond.test_loader:Loader',
++    tests_require=['mock'],
+     )
+
+Index: trytond/trytond/model/modelsql.py
+===================================================================
+
+--- a/trytond/trytond/model/modelsql.py
++++ b/trytond/trytond/model/modelsql.py
+@@ -811,9 +811,9 @@
+                 if hasattr(field, 'set'):
+                     fields_to_set.setdefault(fname, []).extend((ids, value))
+
+-            field_names = cls._fields.keys()
++            field_names = values.keys()
+             cls._update_mptt(field_names, [ids] * len(field_names), values)
+-            all_field_names |= set(values.keys())
++            all_field_names |= set(field_names)
+
+         for fname, fargs in fields_to_set.iteritems():
+             field = cls._fields[fname]
+
+Index: trytond/trytond/tests/test_mptt.py
+===================================================================
+
+--- a/trytond/trytond/tests/test_mptt.py
++++ b/trytond/trytond/tests/test_mptt.py
+@@ -3,6 +3,7 @@
+ #this repository contains the full copyright notices and license terms.
+ import sys
+ import unittest
++from mock import patch
+ from trytond.tests.test_tryton import POOL, DB_NAME, USER, CONTEXT, \
+         install_module
+ from trytond.transaction import Transaction
+@@ -163,6 +164,23 @@
+
+             transaction.cursor.rollback()
+
++    def test0060_update_only_if_parent_is_modified(self):
++        'The left and right fields must only be updated if parent is modified'
++        with Transaction().start(DB_NAME, USER, context=CONTEXT):
++            records = self.mptt.search([
++                    ('parent', '=', None),
++                    ])
++            with patch.object(self.mptt, '_update_tree') as mock:
++                self.mptt.write(records, {'name': 'Parent Records'})
++                self.assertFalse(mock.called)
++
++                first_parent, second_parent = records[:2]
++                self.mptt.write(list(first_parent.childs), {
++                        'parent': second_parent.id,
++                        })
++
++                self.assertTrue(mock.called)
++
+
+ def suite():
+     return unittest.TestLoader().loadTestsFromTestCase(MPTTTestCase)
+
diff --git a/series b/series
index 3997df7..d72b63d 100644
--- a/series
+++ b/series
@@ -28,3 +28,4 @@ issue9511002_1.diff
 issue8481003_1.diff
 issue7461002_1.diff
 issue6441002_20001.diff
+issue6451002_60001.diff