diff --git a/addons/web/static/src/legacy/js/fields/relational_fields.js b/addons/web/static/src/legacy/js/fields/relational_fields.js
index e16e66a3774..fdbe1ea30d4 100644
--- a/addons/web/static/src/legacy/js/fields/relational_fields.js
+++ b/addons/web/static/src/legacy/js/fields/relational_fields.js
@@ -3449,14 +3449,6 @@ var FieldRadio = FieldSelection.extend({
         return checked.length ? checked : this.$("[data-index='0']");
     },
 
-    /**
-     * @override
-     * @returns {boolean} always true
-     */
-    isSet: function () {
-        return true;
-    },
-
     /**
      * Associates the 'for' attribute to the radiogroup, instead of the selected
      * radio button.
diff --git a/addons/web/static/tests/legacy/fields/relational_fields_tests.js b/addons/web/static/tests/legacy/fields/relational_fields_tests.js
index 23558857b3b..a7473396140 100644
--- a/addons/web/static/tests/legacy/fields/relational_fields_tests.js
+++ b/addons/web/static/tests/legacy/fields/relational_fields_tests.js
@@ -2329,6 +2329,34 @@ QUnit.module('relational_fields', {
         form.destroy();
     });
 
+    QUnit.test('required fieldradio widget on a many2one', async function (assert) {
+        assert.expect(6);
+
+        const form = await createView({
+            View: FormView,
+            model: 'partner',
+            data: this.data,
+            arch: '<form>' +
+                '<field name="product_id" widget="radio" required="1"/>' +
+                '</form>',
+        });
+
+        testUtils.mock.intercept(form, 'call_service', function (event) {
+            if (event.data.service === 'notification' && event.data.method === 'notify') {
+                assert.step('danger');
+                assert.equal(event.data.args[0].type, 'danger');
+                assert.equal(event.data.args[0].title, 'Invalid fields:');
+                assert.equal(event.data.args[0].message, '<ul><li>Product</li></ul>');
+            }
+        });
+
+        assert.containsNone(form, 'input:checked', "none of the input should be checked");
+
+        await testUtils.form.clickSave(form);
+        assert.verifySteps(['danger']);
+        form.destroy();
+    });
+
     QUnit.test('fieldradio change value by onchange', async function (assert) {
         assert.expect(4);