diff --git a/addons/web/static/tests/legacy/core/widget_tests.js b/addons/web/static/tests/legacy/core/widget_tests.js
index bd459904d90..512dacbe439 100644
--- a/addons/web/static/tests/legacy/core/widget_tests.js
+++ b/addons/web/static/tests/legacy/core/widget_tests.js
@@ -1,13 +1,12 @@
 /** @odoo-module **/
 
 import AjaxService from "@web/legacy/js/services/ajax_service";
-import core from "@web/legacy/js/services/core";
 import Dialog from "@web/legacy/js/core/dialog";
-import QWeb from "@web/legacy/js/core/qweb";
 import Widget from "@web/legacy/js/core/widget";
 import session from "web.session";
 import { patchWithCleanup } from "@web/../tests/helpers/utils";
 import testUtils from "@web/../tests/legacy/helpers/test_utils";
+import { renderToString } from "@web/core/utils/render";
 
 QUnit.module('core', {}, function () {
 
@@ -180,22 +179,18 @@ QUnit.module('core', {}, function () {
     QUnit.test('template', function (assert) {
         assert.expect(3);
 
-        core.qweb.add_template(
-            '<no>' +
-                '<t t-name="test.widget.template">' +
-                    '<ol>' +
-                        '<li t-foreach="5" t-as="counter" ' +
-                            't-attf-class="class-#{counter}">' +
-                            '<input/>' +
-                            '<t t-esc="counter"/>' +
-                        '</li>' +
-                    '</ol>' +
-                '</t>' +
-            '</no>'
+        renderToString.app.addTemplate(
+            "test.widget.template.1",
+            `<ol>
+                <li t-foreach="[0, 1, 2, 3, 4]" t-as="counter" t-key="counter_index" t-attf-class="class-#{counter}">
+                    <input/>
+                    <t t-esc="counter"/>
+                </li>
+            </ol>`
         );
 
         var widget = new (Widget.extend({
-            template: 'test.widget.template'
+            template: 'test.widget.template.1'
         }))();
         widget.renderElement();
 
@@ -209,15 +204,14 @@ QUnit.module('core', {}, function () {
         assert.expect(4);
         var $fix = $( "#qunit-fixture");
 
-        core.qweb.add_template(
-            '<no>' +
-                '<t t-name="test.widget.template">' +
-                    '<p><t t-esc="widget.value"/></p>' +
-                '</t>' +
-            '</no>'
+        renderToString.app.addTemplate(
+            "test.widget.template.2",
+            `<p>
+                <t t-esc="widget.value"/>
+            </p>`
         );
         var widget = new (Widget.extend({
-            template: 'test.widget.template'
+            template: 'test.widget.template.2'
         }))();
         widget.value = 42;
 
@@ -234,35 +228,23 @@ QUnit.module('core', {}, function () {
     });
 
 
-    QUnit.module('Widgets, with QWeb', {
-        beforeEach: function() {
-            this.oldQWeb = core.qweb;
-            core.qweb = new QWeb();
-            core.qweb.add_template(
-                '<no>' +
-                    '<t t-name="test.widget.template">' +
-                        '<ol>' +
-                            '<li t-foreach="5" t-as="counter" ' +
-                                't-attf-class="class-#{counter}">' +
-                                '<input/>' +
-                                '<t t-esc="counter"/>' +
-                            '</li>' +
-                        '</ol>' +
-                    '</t>' +
-                '</no>'
-            );
-        },
-        afterEach: function() {
-            core.qweb = this.oldQWeb;
-        },
-    });
+    QUnit.module('Widgets, with QWeb');
 
     QUnit.test('basic-alias', function (assert) {
         assert.expect(1);
 
+        renderToString.app.addTemplate(
+            "test.widget.template.3",
+            `<ol>
+                <li t-foreach="[0,1,2,3,4]" t-as="counter" t-key="counter_index" t-attf-class="class-#{counter}">
+                    <input/>
+                    <t t-esc="counter"/>
+                </li>
+            </ol>`
+        );
 
         var widget = new (Widget.extend({
-            template: 'test.widget.template'
+            template: 'test.widget.template.3'
         }))();
         widget.renderElement();
 
@@ -275,9 +257,19 @@ QUnit.module('core', {}, function () {
     QUnit.test('delegate', async function (assert) {
         assert.expect(5);
 
+        renderToString.app.addTemplate(
+            "test.widget.template.4",
+            `<ol>
+                <li t-foreach="[0,1,2,3,4]" t-as="counter" t-key="counter_index" t-attf-class="class-#{counter}">
+                    <input/>
+                    <t t-esc="counter"/>
+                </li>
+            </ol>`
+        );
+
         var a = [];
         var widget = new (Widget.extend({
-            template: 'test.widget.template',
+            template: 'test.widget.template.4',
             events: {
                 'click': function () {
                     a[0] = true;
@@ -303,11 +295,21 @@ QUnit.module('core', {}, function () {
     QUnit.test('undelegate', async function (assert) {
         assert.expect(4);
 
+        renderToString.app.addTemplate(
+            "test.widget.template.5",
+            `<ol>
+                <li t-foreach="[0,1,2,3,4]" t-as="counter" t-key="counter_index" t-attf-class="class-#{counter}">
+                    <input/>
+                    <t t-esc="counter"/>
+                </li>
+            </ol>`
+        );
+
         var clicked = false;
         var newclicked = false;
 
         var widget = new (Widget.extend({
-            template: 'test.widget.template',
+            template: 'test.widget.template.5',
             events: { 'click li': function () { clicked = true; } }
         }))();