diff --git a/entity_body_class.module b/entity_body_class.module
index f31f319fb9547ae1646600956ca147030353b3f4..68b7d7335f73622ec1b12ce08f6e13339627c3fa 100644
--- a/entity_body_class.module
+++ b/entity_body_class.module
@@ -33,7 +33,7 @@ function entity_body_class_help($route_name, RouteMatchInterface $route_match) {
 function entity_body_class_entity_base_field_info(EntityTypeInterface $entity_type) {
   $fields = [];
 
-  if (in_array('Drupal\Core\Entity\ContentEntityInterface', class_implements($entity_type->getOriginalClass())) &&
+  if (in_array(ContentEntityInterface::class, class_implements($entity_type->getOriginalClass())) &&
     $entity_type->getLinkTemplate('canonical')
   ) {
     $fields['entity_body_class'] = BaseFieldDefinition::create('string')
diff --git a/src/EntityBodyClassPermissions.php b/src/EntityBodyClassPermissions.php
index 5d4a35cbc1e8e76db3c32e61b61039a31f026652..b00dde1b1b08efb8032f7ed94a13a9bd021f1ac1 100644
--- a/src/EntityBodyClassPermissions.php
+++ b/src/EntityBodyClassPermissions.php
@@ -3,6 +3,7 @@
 namespace Drupal\entity_body_class;
 
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
+use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -48,7 +49,7 @@ class EntityBodyClassPermissions implements ContainerInjectionInterface {
     $permissions = [];
 
     foreach ($this->entityTypeManager->getDefinitions() as $definition) {
-      if (in_array('Drupal\Core\Entity\ContentEntityInterface', class_implements($definition->getOriginalClass())) &&
+      if (in_array(ContentEntityInterface::class, class_implements($definition->getOriginalClass())) &&
         $definition->getLinkTemplate('canonical')
       ) {
         $permissions["access {$definition->id()} body class field"] = [
diff --git a/src/Form/EntityBodyClassForm.php b/src/Form/EntityBodyClassForm.php
index e38b1c1b8109590ba30e4594c69f710a2db60164..99631961723239828b4a874e445b91bfddcf1f77 100644
--- a/src/Form/EntityBodyClassForm.php
+++ b/src/Form/EntityBodyClassForm.php
@@ -3,6 +3,7 @@
 namespace Drupal\entity_body_class\Form;
 
 use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Form\ConfigFormBase;
 use Drupal\Core\Form\FormStateInterface;
@@ -73,7 +74,7 @@ class EntityBodyClassForm extends ConfigFormBase {
     ];
 
     foreach ($this->entityTypeManager->getDefinitions() as $definition) {
-      if (in_array('Drupal\Core\Entity\ContentEntityInterface', class_implements($definition->getOriginalClass())) &&
+      if (in_array(ContentEntityInterface::class, class_implements($definition->getOriginalClass())) &&
         $definition->getLinkTemplate('canonical')
       ) {
         $id = $definition->id();