diff --git a/odoo/addons/test_testing_utilities/ir.model.access.csv b/odoo/addons/test_testing_utilities/ir.model.access.csv
index ced191d38e2..697a7334581 100644
--- a/odoo/addons/test_testing_utilities/ir.model.access.csv
+++ b/odoo/addons/test_testing_utilities/ir.model.access.csv
@@ -12,3 +12,5 @@ access_test_testing_utilities_parent,access_test_testing_utilities_parent,model_
 access_test_testing_utilities_sub,access_test_testing_utilities_sub,model_test_testing_utilities_sub,,1,0,0,0
 access_test_testing_utilities_sub2,access_test_testing_utilities_sub2,model_test_testing_utilities_sub2,,1,0,0,0
 access_test_testing_utilities_sub3,access_test_testing_utilities_sub3,model_test_testing_utilities_sub3,,1,0,0,0
+access_test_testing_utilities_onchange_parent,access_test_testing_utilities_onchange_parent,model_test_testing_utilities_onchange_parent,,1,0,0,0
+access_test_testing_utilities_onchange_line,access_test_testing_utilities_onchange_line,model_test_testing_utilities_onchange_line,,1,0,0,0
diff --git a/odoo/addons/test_testing_utilities/menu.xml b/odoo/addons/test_testing_utilities/menu.xml
index 0ca37f58658..fa5263efeca 100644
--- a/odoo/addons/test_testing_utilities/menu.xml
+++ b/odoo/addons/test_testing_utilities/menu.xml
@@ -104,4 +104,25 @@
             </form>
         </field>
     </record>
+
+    <record id="m2o_onchange_view" model="ir.ui.view">
+        <field name="name">Dynamic Onchange Test View</field>
+        <field name="model">test_testing_utilities.onchange_parent</field>
+        <field name="arch" type="xml">
+            <form>
+                <sheet>
+                    <notebook>
+                        <page>
+                            <field name="line_ids" widget="one2many_list" context="{'line_ids': line_ids}">
+                                <tree editable="bottom">
+                                    <field name="dummy"/>
+                                    <field name="flag" invisible="1" readonly="1"/>
+                                </tree>
+                            </field>
+                        </page>
+                    </notebook>
+                </sheet>
+            </form>
+        </field>
+    </record>
 </odoo>
diff --git a/odoo/addons/test_testing_utilities/models.py b/odoo/addons/test_testing_utilities/models.py
index 2bb6e5e5dd6..8d911e2135c 100644
--- a/odoo/addons/test_testing_utilities/models.py
+++ b/odoo/addons/test_testing_utilities/models.py
@@ -169,3 +169,26 @@ class O2MSub3(models.Model):
     def _compute_name(self):
         for r in self:
             r.name = str(r.v)
+
+
+class O2MOnchangeParent(models.Model):
+    _name = 'test_testing_utilities.onchange_parent'
+
+    line_ids = fields.One2many('test_testing_utilities.onchange_line', 'parent')
+
+    @api.onchange('line_ids')
+    def _onchange_line_ids(self):
+        for line in self.line_ids.filtered(lambda l: l.flag):
+            self.env['test_testing_utilities.onchange_line'].new({'parent': self.id})
+
+
+class M2OOnchangeLine(models.Model):
+    _name = 'test_testing_utilities.onchange_line'
+
+    parent = fields.Many2one('test_testing_utilities.onchange_parent')
+    dummy = fields.Float()
+    flag = fields.Boolean(store=False)
+
+    @api.onchange('dummy')
+    def _onchange_flag(self):
+        self.flag = True
diff --git a/odoo/addons/test_testing_utilities/tests/test_form_impl.py b/odoo/addons/test_testing_utilities/tests/test_form_impl.py
index 2806a972335..2232e872dc6 100644
--- a/odoo/addons/test_testing_utilities/tests/test_form_impl.py
+++ b/odoo/addons/test_testing_utilities/tests/test_form_impl.py
@@ -393,6 +393,17 @@ class TestO2M(TransactionCase):
         with self.assertRaises(AssertionError):
             f.subs.remove(index=0)
 
+    def test_o2m_dyn_onchange(self):
+        f = Form(self.env['test_testing_utilities.onchange_parent'], view='test_testing_utilities.m2o_onchange_view')
+
+        with f.line_ids.new() as new_line:
+            new_line.dummy = 42
+            self.assertTrue(new_line.flag)
+
+        with f.line_ids.edit(index=0) as new_line:
+            self.assertTrue(new_line.flag)
+
+
 class TestEdition(TransactionCase):
     """ These use the context manager form as we don't need the record
     post-save (we already have it) and it's easier to see what bits act on
diff --git a/odoo/tests/common.py b/odoo/tests/common.py
index 7e974a96656..c26a8e5323a 100644
--- a/odoo/tests/common.py
+++ b/odoo/tests/common.py
@@ -955,7 +955,6 @@ class Form(object):
 
         # marks any onchange source as changed (default_get or explicit set)
         self._changed.update(fields)
-
         result = self._model.onchange(
             self._onchange_values(),
             fields,
@@ -1071,6 +1070,25 @@ class O2MForm(Form):
         # FIXME: should be called when performing on change => value needs to be serialised into parent every time?
         proxy._parent._perform_onchange([proxy._field])
 
+    def _values_to_save(self):
+        """ Validates values and returns only fields modified since
+        load/save
+        """
+        values = {}
+        for f in self._view['fields']:
+            v = self._values[f]
+            if self._get_modifier(f, 'required'):
+                assert v is not False, "{} is a required field".format(f)
+
+            # skip unmodified fields
+            if f not in self._changed:
+                continue
+            # if self._get_modifier(f, 'readonly'):
+            #     continue
+            # TODO: filter out (1, _, {}) from o2m values
+            values[f] = v
+        return values
+
 class X2MProxy(object):
     _parent = None
     _field = None