diff --git a/src/JsonApiResource/ResourceObject.php b/src/JsonApiResource/ResourceObject.php
index 93dc25d..eabc629 100644
--- a/src/JsonApiResource/ResourceObject.php
+++ b/src/JsonApiResource/ResourceObject.php
@@ -138,15 +138,7 @@ 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.
-    $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 = $entity->label();
-    }
+    static::ensureLabelFieldValue($entity, $fields);
 
     // Return a sub-array of $output containing the keys in $enabled_fields.
     $input = array_intersect_key($fields, array_flip($enabled_field_names));
@@ -186,4 +178,25 @@ 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 e2a1313..6762bed 100644
--- a/src/LabelOnlyEntity.php
+++ b/src/LabelOnlyEntity.php
@@ -2,8 +2,9 @@
 
 namespace Drupal\jsonapi;
 
+use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityInterface;
-use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\TypedData\TypedDataInternalPropertiesHelper;
 use Drupal\jsonapi\JsonApiResource\ResourceObject;
 
 /**
@@ -27,12 +28,14 @@ final class LabelOnlyEntity extends ResourceObject {
    * {@inheritdoc}
    */
   protected function extractFields(EntityInterface $entity) {
-    if (!$entity instanceof FieldableEntityInterface) {
+    if (!$entity instanceof ContentEntityInterface) {
       return [];
     }
+    $fields = TypedDataInternalPropertiesHelper::getNonInternalProperties($entity->getTypedData());
+    static::ensureLabelFieldValue($entity, $fields);
     $label_field_name = $this->getLabelFieldName();
     return $label_field_name && $this->resourceType->isFieldEnabled($label_field_name) ?
-      [$this->resourceType->getPublicName($label_field_name) => $entity->get($label_field_name)]
+      [$this->resourceType->getPublicName($label_field_name) => $fields[$label_field_name]]
       : [];
   }