diff --git a/addons/web/static/src/js/views/basic/basic_model.js b/addons/web/static/src/js/views/basic/basic_model.js
index 8798e8cdb2e..3591ac3cf94 100644
--- a/addons/web/static/src/js/views/basic/basic_model.js
+++ b/addons/web/static/src/js/views/basic/basic_model.js
@@ -2595,6 +2595,7 @@ var BasicModel = AbstractModel.extend({
                     _.each(relRecordUpdated, function (relRecord) {
                         var changes = self._generateChanges(relRecord, options);
                         if (!_.isEmpty(changes)) {
+                            delete changes.id;
                             var command = x2ManyCommands.update(relRecord.res_id, changes);
                             commands[fieldName].push(command);
                         }
@@ -2626,9 +2627,8 @@ var BasicModel = AbstractModel.extend({
                             relRecord = _.findWhere(relRecordAdded, {res_id: list.res_ids[i]});
                             changes = this._generateChanges(relRecord, options);
                             if ('id' in changes) {
-                                var id = changes.id;
                                 delete changes.id;
-                                commands[fieldName].push(x2ManyCommands.update(id, changes));
+                                commands[fieldName].push(x2ManyCommands.update(relRecord.res_id, changes));
                             } else {
                                 commands[fieldName].push(x2ManyCommands.create(changes));
                             }
diff --git a/addons/web/static/tests/fields/relational_fields_tests.js b/addons/web/static/tests/fields/relational_fields_tests.js
index 5677443aa0f..b116f10de86 100644
--- a/addons/web/static/tests/fields/relational_fields_tests.js
+++ b/addons/web/static/tests/fields/relational_fields_tests.js
@@ -6633,6 +6633,42 @@ QUnit.module('relational_fields', {
         form.destroy();
     });
 
+    QUnit.test('default_get, onchange, onchange on m2m', function (assert) {
+        assert.expect(1);
+
+        this.data.partner.onchanges.int_field = function (obj) {
+            if (obj.int_field === 2) {
+                assert.deepEqual(obj.timmy, [
+                    [6, false, [12]],
+                    [1, 12, {display_name: 'gold'}]
+                ]);
+            }
+            obj.timmy = [
+                [5],
+                [1, 12, {display_name: 'gold'}]
+            ];
+        };
+
+        var form = createView({
+            View: FormView,
+            model: 'partner',
+            data: this.data,
+            arch: '<form>' +
+                    '<sheet>' +
+                        '<field name="timmy">' +
+                            '<tree>' +
+                                '<field name="display_name"/>' +
+                            '</tree>' +
+                        '</field>' +
+                        '<field name="int_field"/>' +
+                    '</sheet>' +
+                '</form>',
+        });
+
+        form.$('.o_field_widget[name=int_field]').val(2).trigger('input');
+        form.destroy();
+    });
+
     QUnit.module('FieldStatus');
 
     QUnit.test('static statusbar widget on many2one field', function (assert) {