diff --git a/src/Document/Resource/ResourceObject.php b/src/Document/Resource/ResourceObject.php
index 4b8c595..a9d3950 100644
--- a/src/Document/Resource/ResourceObject.php
+++ b/src/Document/Resource/ResourceObject.php
@@ -14,7 +14,7 @@
 use JsonApiPhp\JsonApi\Document\LinksTrait;
 use JsonApiPhp\JsonApi\Document\Resource\Relationship\Relationship;
 
-final class ResourceObject extends ResourceIdentifier
+class ResourceObject extends ResourceIdentifier
 {
     use LinksTrait;