diff --git a/core/modules/comment/lib/Drupal/comment/Comment.php b/core/modules/comment/lib/Drupal/comment/Comment.php
index a7bacd4..7b9554b 100644
--- a/core/modules/comment/lib/Drupal/comment/Comment.php
+++ b/core/modules/comment/lib/Drupal/comment/Comment.php
@@ -7,12 +7,13 @@
 
 namespace Drupal\comment;
 
+use Drupal\entity\ContentEntityInterface;
 use Drupal\entity\Entity;
 
 /**
  * Defines the comment entity class.
  */
-class Comment extends Entity {
+class Comment extends Entity implements ContentEntityInterface {
 
   /**
    * The comment ID.
diff --git a/core/modules/node/lib/Drupal/node/Node.php b/core/modules/node/lib/Drupal/node/Node.php
index fd3454e..a96f309 100644
--- a/core/modules/node/lib/Drupal/node/Node.php
+++ b/core/modules/node/lib/Drupal/node/Node.php
@@ -7,12 +7,13 @@
 
 namespace Drupal\node;
 
+use Drupal\entity\ContentEntityInterface;
 use Drupal\entity\Entity;
 
 /**
  * Defines the node entity class.
  */
-class Node extends Entity {
+class Node extends Entity implements ContentEntityInterface {
 
   /**
    * The node ID.
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Term.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Term.php
index 929422c..87d823a 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/Term.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Term.php
@@ -7,12 +7,13 @@
 
 namespace Drupal\taxonomy;
 
+use Drupal\entity\ContentEntityInterface;
 use Drupal\entity\Entity;
 
 /**
  * Defines the taxonomy term entity.
  */
-class Term extends Entity {
+class Term extends Entity implements ContentEntityInterface {
 
   /**
    * The taxonomy term ID.