diff --git a/core/modules/config/tests/src/Functional/ConfigEntityFormOverrideTest.php b/core/modules/config/tests/src/Functional/ConfigEntityFormOverrideTest.php
index 0ba75ac108..2f48a7c6ff 100644
--- a/core/modules/config/tests/src/Functional/ConfigEntityFormOverrideTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigEntityFormOverrideTest.php
@@ -46,7 +46,7 @@ public function testFormsWithOverrides() {
     // Test that the original label on the editing page is intact.
     $this->drupalGet('admin/structure/config_test/manage/dotted.default');
     $elements = $this->xpath('//input[@name="label"]');
-    $this->assertIdentical((string) $elements[0]['value'], $original_label);
+    $this->assertIdentical((string) $elements[0]->getValue(), $original_label);
     $this->assertNoText($overridden_label);
 
     // Change to a new label and test that the listing now has the edited label.
@@ -61,7 +61,7 @@ public function testFormsWithOverrides() {
     // Test that the editing page now has the edited label.
     $this->drupalGet('admin/structure/config_test/manage/dotted.default');
     $elements = $this->xpath('//input[@name="label"]');
-    $this->assertIdentical((string) $elements[0]['value'], $edited_label);
+    $this->assertIdentical((string) $elements[0]->getValue(), $edited_label);
 
     // Test that the overridden label is still loaded with the entity.
     $this->assertEqual($config_test_storage->load('dotted.default')->label(), $overridden_label);
diff --git a/core/modules/config/tests/src/Functional/ConfigEntityListTest.php b/core/modules/config/tests/src/Functional/ConfigEntityListTest.php
index 90392b6329..69ef79762f 100644
--- a/core/modules/config/tests/src/Functional/ConfigEntityListTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigEntityListTest.php
@@ -168,7 +168,7 @@ public function testListUI() {
     // Test the contents of each th cell.
     $expected_items = ['Label', 'Machine name', 'Operations'];
     foreach ($elements as $key => $element) {
-      $this->assertIdentical((string) $element[0], $expected_items[$key]);
+      $this->assertIdentical($element->getText(), $expected_items[$key]);
     }
 
     // Check the number of table row cells.
@@ -178,9 +178,9 @@ public function testListUI() {
     // Check the contents of each row cell. The first cell contains the label,
     // the second contains the machine name, and the third contains the
     // operations list.
-    $this->assertIdentical((string) $elements[0], 'Default');
-    $this->assertIdentical((string) $elements[1], 'dotted.default');
-    $this->assertTrue($elements[2]->children()->xpath('//ul'), 'Operations list found.');
+    $this->assertIdentical($elements[0]->getText(), 'Default');
+    $this->assertIdentical($elements[1]->getText(), 'dotted.default');
+    $this->assertNotEmpty($elements[2]->find('xpath', '//ul'), 'Operations list found.');
 
     // Add a new entity using the operations link.
     $this->assertLink('Add test configuration');
diff --git a/core/modules/config/tests/src/Functional/ConfigFormOverrideTest.php b/core/modules/config/tests/src/Functional/ConfigFormOverrideTest.php
index f267561d2a..59276e35f1 100644
--- a/core/modules/config/tests/src/Functional/ConfigFormOverrideTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigFormOverrideTest.php
@@ -32,7 +32,7 @@ public function testFormsWithOverrides() {
     $this->drupalGet('admin/config/system/site-information');
     $this->assertTitle('Basic site settings | ' . $overridden_name);
     $elements = $this->xpath('//input[@name="site_name"]');
-    $this->assertIdentical((string) $elements[0]['value'], 'Drupal');
+    $this->assertIdentical((string) $elements[0]->getValue(), 'Drupal');
 
     // Submit the form and ensure the site name is not changed.
     $edit = [
@@ -41,7 +41,7 @@ public function testFormsWithOverrides() {
     $this->drupalPostForm('admin/config/system/site-information', $edit, t('Save configuration'));
     $this->assertTitle('Basic site settings | ' . $overridden_name);
     $elements = $this->xpath('//input[@name="site_name"]');
-    $this->assertIdentical((string) $elements[0]['value'], $edit['site_name']);
+    $this->assertIdentical((string) $elements[0]->getValue(), $edit['site_name']);
   }
 
 }
diff --git a/core/modules/config/tests/src/Functional/ConfigInstallWebTest.php b/core/modules/config/tests/src/Functional/ConfigInstallWebTest.php
index a28a5b4fd7..b12f17eb19 100644
--- a/core/modules/config/tests/src/Functional/ConfigInstallWebTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigInstallWebTest.php
@@ -156,7 +156,7 @@ public function testPreExistingConfigInstall() {
     // override created still exists.
     $this->drupalGet('admin/appearance');
     $url = $this->xpath("//a[contains(@href,'config_clash_test_theme') and contains(@href,'/install?')]/@href")[0];
-    $this->drupalGet($this->getAbsoluteUrl($url));
+    $this->drupalGet($this->getAbsoluteUrl($url->getText()));
     $this->assertRaw('Unable to install config_clash_test_theme, <em class="placeholder">config_test.dynamic.dotted.default, language/fr/config_test.dynamic.dotted.default</em> already exist in active configuration.');
 
     // Test installing a theme through the API that has existing configuration.