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 445967287bf..7e702e30862 100644
--- a/addons/web/static/src/js/views/basic/basic_model.js
+++ b/addons/web/static/src/js/views/basic/basic_model.js
@@ -949,8 +949,8 @@ var BasicModel = AbstractModel.extend({
      */
     addFieldsInfo: function (recordID, viewInfo) {
         var record = this.localData[recordID];
-        record.fields = _.defaults(record.fields, viewInfo.fields);
-        record.fieldsInfo = _.defaults(record.fieldsInfo, viewInfo.fieldsInfo);
+        record.fields = _.extend({}, record.fields, viewInfo.fields);
+        record.fieldsInfo = _.extend({}, record.fieldsInfo, viewInfo.fieldsInfo);
     },
     /**
      * Manually sets a resource as dirty. This is used to notify that a field
diff --git a/addons/web/static/tests/fields/relational_fields_tests.js b/addons/web/static/tests/fields/relational_fields_tests.js
index 8f789c88647..8a67f6eec05 100644
--- a/addons/web/static/tests/fields/relational_fields_tests.js
+++ b/addons/web/static/tests/fields/relational_fields_tests.js
@@ -135,6 +135,7 @@ QUnit.module('relational_fields', {
                     partner_ids: [],
                     turtle_ref: 'product,37',
                 }],
+                onchanges: {},
             },
             user: {
                 fields: {
@@ -2677,6 +2678,45 @@ QUnit.module('relational_fields', {
         form.destroy();
     });
 
+    QUnit.test('edition of one2many field, with onchange and not inline sub view', function (assert) {
+        assert.expect(2);
+
+        this.data.turtle.onchanges.turtle_int = function (obj) {
+            obj.turtle_foo = String(obj.turtle_int);
+        };
+        this.data.partner.onchanges.turtles = function () {};
+
+        var form = createView({
+            View: FormView,
+            model: 'partner',
+            data: this.data,
+            arch: '<form string="Partners">' +
+                    '<field name="turtles"/>' +
+                '</form>',
+            archs: {
+                'turtle,false,list': '<tree><field name="turtle_foo"/></tree>',
+                'turtle,false,form': '<form><group><field name="turtle_foo"/><field name="turtle_int"/></group></form>',
+            },
+            mockRPC: function (route, args) {
+                return this._super.apply(this, arguments);
+            },
+            res_id: 1,
+        });
+        form.$buttons.find('.o_form_button_edit').click();
+        form.$('.o_field_x2many_list_row_add a').click();
+        $('input[name="turtle_int"]').val('5').trigger('input');
+        $('.modal-footer button.btn-primary').first().click();
+        assert.strictEqual(form.$('tbody tr:eq(1) td.o_data_cell').text(), '5',
+            'should display 5 in the foo field');
+        form.$('tbody tr:eq(1) td.o_data_cell').click();
+
+        $('input[name="turtle_int"]').val('3').trigger('input');
+        $('.modal-footer button.btn-primary').first().click();
+        assert.strictEqual(form.$('tbody tr:eq(1) td.o_data_cell').text(), '3',
+            'should now display 3 in the foo field');
+        form.destroy();
+    });
+
     QUnit.test('sorting one2many fields', function (assert) {
         assert.expect(4);
 
diff --git a/addons/web/static/tests/helpers/mock_server.js b/addons/web/static/tests/helpers/mock_server.js
index 76391e4cb7a..f78de2f5c0b 100644
--- a/addons/web/static/tests/helpers/mock_server.js
+++ b/addons/web/static/tests/helpers/mock_server.js
@@ -32,9 +32,6 @@ var MockServer = Class.extend({
             if (!('name' in model.fields)) {
                 model.fields.name = {string: "Name", type: "char", default: "name"};
             }
-            for (var fieldName in model.onchanges) {
-                model.fields[fieldName].onChange = "1";
-            }
             model.records = model.records || [];
 
             for (var i = 0; i < model.records.length; i++) {
@@ -282,7 +279,7 @@ var MockServer = Class.extend({
 
             // add onchanges
             if (name in onchanges) {
-                field.onChange="1";
+                node.attrs.on_change="1";
             }
         });
         return {
diff --git a/addons/web/static/tests/views/basic_model_tests.js b/addons/web/static/tests/views/basic_model_tests.js
index b2a00f1ca09..8de3e3c91a2 100644
--- a/addons/web/static/tests/views/basic_model_tests.js
+++ b/addons/web/static/tests/views/basic_model_tests.js
@@ -203,6 +203,7 @@ QUnit.module('Views', {
     QUnit.test('basic onchange', function (assert) {
         assert.expect(5);
 
+        this.data.partner.fields.foo.onChange = true;
         this.data.partner.onchanges.foo = function (obj) {
             obj.bar = obj.foo.length;
         };
@@ -240,6 +241,7 @@ QUnit.module('Views', {
     QUnit.test('onchange with a many2one', function (assert) {
         assert.expect(5);
 
+        this.data.partner.fields.product_id.onChange = true;
         this.data.partner.onchanges.product_id = function (obj) {
             if (obj.product_id === 37) {
                 obj.foo = "space lollipop";
@@ -280,6 +282,7 @@ QUnit.module('Views', {
     QUnit.test('onchange on a one2many not in view (fieldNames)', function (assert) {
         assert.expect(6);
 
+        this.data.partner.fields.foo.onChange = true;
         this.data.partner.onchanges.foo = function (obj) {
             obj.bar = obj.foo.length;
             obj.product_ids = [];
@@ -425,6 +428,7 @@ QUnit.module('Views', {
     QUnit.test('onchange on a char with an unchanged many2one', function (assert) {
         assert.expect(2);
 
+        this.data.partner.fields.foo.onChange = true;
         this.data.partner.onchanges.foo = function (obj) {
             obj.foo = obj.foo + " alligator";
         };
@@ -453,6 +457,7 @@ QUnit.module('Views', {
     QUnit.test('onchange on a char with another many2one not set to a value', function (assert) {
         assert.expect(2);
         this.data.partner.records[0].product_id = false;
+        this.data.partner.fields.foo.onChange = true;
         this.data.partner.onchanges.foo = function (obj) {
             obj.foo = obj.foo + " alligator";
         };
@@ -1153,6 +1158,7 @@ QUnit.module('Views', {
         assert.expect(4);
 
         this.data.partner.fields.total.default = 50;
+        this.data.partner.fields.product_ids.onChange = true;
         this.data.partner.onchanges.product_ids = function (obj) {
             obj.total += 100;
         };
@@ -1497,6 +1503,7 @@ QUnit.module('Views', {
         assert.expect(6);
 
         this.params.fieldNames = ['foo', 'bar'];
+        this.data.partner.fields.foo.onChange = true;
         this.data.partner.onchanges.foo = function (obj) {
             obj.bar = obj.foo.length;
         };
@@ -1561,6 +1568,7 @@ QUnit.module('Views', {
         assert.expect(6);
 
         this.params.fieldNames = ['foo', 'bar'];
+        this.data.partner.fields.foo.onChange = true;
         this.data.partner.onchanges.foo = function (obj) {
             obj.bar = obj.foo.length;
         };