diff -u b/core/lib/Drupal/Core/Entity/ContentEntityViewBuilder.php b/core/lib/Drupal/Core/Entity/ContentEntityViewBuilder.php
--- b/core/lib/Drupal/Core/Entity/ContentEntityViewBuilder.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityViewBuilder.php
@@ -13,7 +13,7 @@
    * {@inheritdoc}
    */
   protected function alterBuild(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display, $view_mode) {
-    if ($entity->isNew() || !$entity instanceof ContentEntityInterface) {
+    if ($entity->isNew() || !($entity instanceof ContentEntityInterface)) {
       return;
     }
     $key = $entity->getEntityTypeId();
diff -u b/core/modules/block_content/tests/src/Functional/BlockContentContextualLinksTest.php b/core/modules/block_content/tests/src/Functional/BlockContentContextualLinksTest.php
--- b/core/modules/block_content/tests/src/Functional/BlockContentContextualLinksTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentContextualLinksTest.php
@@ -10,9 +10,7 @@
 class BlockContentContextualLinksTest extends BlockContentTestBase {
 
   /**
-   * Modules to enable.
-   *
-   * @var array
+   * {@inheritdoc}
    */
   public static $modules = [
     'contextual',
@@ -33,7 +31,7 @@
     $this->drupalLogin($user);
 
     $this->drupalGet('<front>');
-    $this->assertSession()->responseContains('data-contextual-id="block:block=' . $block->id() . ':langcode=en|block_content:block_content=' . $block_content->id() . ':');
+    $this->assertSession()->elementAttributeContains('css', 'div[data-contextual-id]', 'data-contextual-id', 'block:block=' . $block->id() . ':langcode=en|block_content:block_content=' . $block_content->id() . ':');
   }
 
 }
diff -u b/core/modules/node/tests/src/Functional/NodeContextualLinksTest.php b/core/modules/node/tests/src/Functional/NodeContextualLinksTest.php
--- b/core/modules/node/tests/src/Functional/NodeContextualLinksTest.php
+++ b/core/modules/node/tests/src/Functional/NodeContextualLinksTest.php
@@ -12,9 +12,7 @@
 class NodeContextualLinksTest extends NodeTestBase {
 
   /**
-   * Modules to enable.
-   *
-   * @var array
+   * {@inheritdoc}
    */
   public static $modules = [
     'contextual',
@@ -38,7 +36,7 @@
     $this->drupalLogin($user);
 
     $this->drupalGet('node/' . $node->id());
-    $this->assertSession()->responseContains('data-contextual-id="node:node=' . $node->id() . ':');
+    $this->assertSession()->elementAttributeContains('css', 'div[data-contextual-id]', 'data-contextual-id', 'node:node=' . $node->id() . ':');
   }
 
 }
diff -u b/core/modules/taxonomy/tests/src/Functional/TermContextualLinksTest.php b/core/modules/taxonomy/tests/src/Functional/TermContextualLinksTest.php
--- b/core/modules/taxonomy/tests/src/Functional/TermContextualLinksTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TermContextualLinksTest.php
@@ -10,9 +10,7 @@
 class TermContextualLinksTest extends TaxonomyTestBase {
 
   /**
-   * Modules to enable.
-   *
-   * @var array
+   * {@inheritdoc}
    */
   public static $modules = [
     'contextual',
@@ -32,7 +30,7 @@
     $this->drupalLogin($user);
 
     $this->drupalGet('taxonomy/term/' . $term->id());
-    $this->assertSession()->responseContains('data-contextual-id="taxonomy_term:taxonomy_term=' . $term->id() . ':');
+    $this->assertSession()->elementAttributeContains('css', 'div[data-contextual-id]', 'data-contextual-id', 'taxonomy_term:taxonomy_term=' . $term->id() . ':');
   }
 
 }