diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormPageCacheTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormPageCacheTest.php
index 395e497463..9358023d9f 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormPageCacheTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormPageCacheTest.php
@@ -12,11 +12,9 @@
 class AjaxFormPageCacheTest extends JavascriptTestBase {
 
   /**
-   * Modules to enable.
-   *
-   * @var array
+   * {@inheritdoc}
    */
-  public static $modules = ['node', 'ajax_test', 'ajax_forms_test'];
+  public static $modules = ['ajax_test', 'ajax_forms_test'];
 
   /**
    * {@inheritdoc}
@@ -34,8 +32,8 @@ protected function setUp() {
    */
   protected function getFormBuildId() {
     $build_id_fields = $this->xpath('//input[@name="form_build_id"]');
-    $this->assertEqual(count($build_id_fields), 1, 'One form build id field on the page');
-    return (string) $build_id_fields[0]->getValue();
+    $this->assertEquals(count($build_id_fields), 1, 'One form build id field on the page');
+    return $build_id_fields[0]->getValue();
   }
 
   /**
@@ -43,7 +41,7 @@ protected function getFormBuildId() {
    */
   public function testSimpleAJAXFormValue() {
     $this->drupalGet('ajax_forms_test_get_form');
-    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS', 'Page was not cached.');
+    $this->assertEquals($this->drupalGetHeader('X-Drupal-Cache'), 'MISS', 'Page was not cached.');
     $build_id_initial = $this->getFormBuildId();
 
     $session = $this->getSession();
@@ -52,32 +50,33 @@ public function testSimpleAJAXFormValue() {
     $this->assertSession()->assertWaitOnAjaxRequest();
 
     $build_id_first_ajax = $this->getFormBuildId();
-    $this->assertNotEqual($build_id_initial, $build_id_first_ajax, 'Build id is changed in the form_build_id element on first AJAX submission');
+    $this->assertNotEquals($build_id_initial, $build_id_first_ajax, 'Build id is changed in the form_build_id element on first AJAX submission');
 
     // Changing the value of a select input element, triggers a AJAX request/response.
     $session->getPage()->selectFieldOption('select', 'red');
     $this->assertSession()->assertWaitOnAjaxRequest();
     $build_id_second_ajax = $this->getFormBuildId();
-    $this->assertNotEqual($build_id_first_ajax, $build_id_second_ajax, 'Build id changes on subsequent AJAX submissions');
+    $this->assertNotEquals($build_id_first_ajax, $build_id_second_ajax, 'Build id changes on subsequent AJAX submissions');
 
-    // Repeat the test sequence but this time with a page loaded from the cache.
+    // Emulate a push of the reload button and then repeat the test sequence
+    // this time with a page loaded from the cache.
     $session->reload();
-    $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
+    $this->assertEquals($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
     $build_id_from_cache_initial = $this->getFormBuildId();
-    $this->assertEqual($build_id_initial, $build_id_from_cache_initial, 'Build id is the same as on the first request');
+    $this->assertEquals($build_id_initial, $build_id_from_cache_initial, 'Build id is the same as on the first request');
 
     // Changing the value of a select input element, triggers a AJAX request/response.
     $session->getPage()->selectFieldOption('select', 'green');
     $this->assertSession()->assertWaitOnAjaxRequest();
     $build_id_from_cache_first_ajax = $this->getFormBuildId();
-    $this->assertNotEqual($build_id_from_cache_initial, $build_id_from_cache_first_ajax, 'Build id is changed in the simpletest-DOM on first AJAX submission');
-    $this->assertNotEqual($build_id_first_ajax, $build_id_from_cache_first_ajax, 'Build id from first user is not reused');
+    $this->assertNotEquals($build_id_from_cache_initial, $build_id_from_cache_first_ajax, 'Build id is changed in the simpletest-DOM on first AJAX submission');
+    $this->assertNotEquals($build_id_first_ajax, $build_id_from_cache_first_ajax, 'Build id from first user is not reused');
 
     // Changing the value of a select input element, triggers a AJAX request/response.
     $session->getPage()->selectFieldOption('select', 'red');
     $this->assertSession()->assertWaitOnAjaxRequest();
     $build_id_from_cache_second_ajax = $this->getFormBuildId();
-    $this->assertNotEqual($build_id_from_cache_first_ajax, $build_id_from_cache_second_ajax, 'Build id changes on subsequent AJAX submissions');
+    $this->assertNotEquals($build_id_from_cache_first_ajax, $build_id_from_cache_second_ajax, 'Build id changes on subsequent AJAX submissions');
 
   }
 
@@ -88,8 +87,14 @@ public function testSimpleAJAXFormValue() {
    */
   public function testAjaxElementValidation() {
     $this->drupalGet('ajax_validation_test');
-    $this->getSession()->getPage()->fillField('drivertext', 'some dumb test');
-    $this->assertSession()->assertWaitOnAjaxRequest();
+    // Changing the value of the textfield will trigger an AJAX request/response.
+    $this->getSession()->getPage()->fillField('drivertext', 'some dumb text');
+
+    // When the AJAX command updates the DOM a <ul> unsorted list
+    // "message__list" structure will appear on the page echoing back the
+    // "some dumb text" message.
+    $placeholder = $this->assertSession()->waitForElement('css', "ul.messages__list li.messages__item em:contains('some dumb text')");
+    $this->assertNotNull($placeholder, 'Message structure containing input data located.');
   }
 
 }