diff --git a/src/JsonApiResource/ResourceObject.php b/src/JsonApiResource/ResourceObject.php
index eabc629..93dc25d 100644
--- a/src/JsonApiResource/ResourceObject.php
+++ b/src/JsonApiResource/ResourceObject.php
@@ -138,7 +138,15 @@ class ResourceObject implements CacheableDependencyInterface, ResourceIdentifier
 
     // The "label" field needs special treatment: some entity types have a label
     // field that is actually backed by a label callback.
-    static::ensureLabelFieldValue($entity, $fields);
+    $entity_type = $entity->getEntityType();
+    if ($entity_type->hasLabelCallback()) {
+      $label_field_name = $entity_type->getKey('label');
+      // @todo Remove this work-around after https://www.drupal.org/project/drupal/issues/2450793 lands.
+      if ($entity->getEntityTypeId() === 'user') {
+        $label_field_name = 'name';
+      }
+      $fields[$label_field_name]->value = $entity->label();
+    }
 
     // Return a sub-array of $output containing the keys in $enabled_fields.
     $input = array_intersect_key($fields, array_flip($enabled_field_names));
@@ -178,25 +186,4 @@ class ResourceObject implements CacheableDependencyInterface, ResourceIdentifier
     return $enabled_public_fields;
   }
 
-  /**
-   * Ensures an entity's label field value is present.
-   *
-   * @param \Drupal\Core\Entity\ContentEntityInterface $entity
-   *   The entity for which to ensure a label field value is present.
-   * @param \Drupal\Core\Field\FieldItemListInterface[] $fields
-   *   The array of entity fields on which to ensure the label field value is
-   *   present.
-   */
-  protected static function ensureLabelFieldValue(ContentEntityInterface $entity, array &$fields) {
-    $entity_type = $entity->getEntityType();
-    if ($entity_type->hasLabelCallback()) {
-      $label_field_name = $entity_type->getKey('label');
-      // @todo Remove this work-around after https://www.drupal.org/project/drupal/issues/2450793 lands.
-      if ($entity->getEntityTypeId() === 'user') {
-        $label_field_name = 'name';
-      }
-      $fields[$label_field_name]->value = $entity->label();
-    }
-  }
-
 }
diff --git a/src/LabelOnlyEntity.php b/src/LabelOnlyEntity.php
index 6762bed..a770eb4 100644
--- a/src/LabelOnlyEntity.php
+++ b/src/LabelOnlyEntity.php
@@ -2,9 +2,7 @@
 
 namespace Drupal\jsonapi;
 
-use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityInterface;
-use Drupal\Core\TypedData\TypedDataInternalPropertiesHelper;
 use Drupal\jsonapi\JsonApiResource\ResourceObject;
 
 /**
@@ -28,11 +26,7 @@ final class LabelOnlyEntity extends ResourceObject {
    * {@inheritdoc}
    */
   protected function extractFields(EntityInterface $entity) {
-    if (!$entity instanceof ContentEntityInterface) {
-      return [];
-    }
-    $fields = TypedDataInternalPropertiesHelper::getNonInternalProperties($entity->getTypedData());
-    static::ensureLabelFieldValue($entity, $fields);
+    $fields = parent::extractFields($entity);
     $label_field_name = $this->getLabelFieldName();
     return $label_field_name && $this->resourceType->isFieldEnabled($label_field_name) ?
       [$this->resourceType->getPublicName($label_field_name) => $fields[$label_field_name]]