diff --git a/src/Symfony/Component/Serializer/Extractor/ObjectPropertyListExtractor.php b/src/Symfony/Component/Serializer/Extractor/ObjectPropertyListExtractor.php
index 922094f8cb45a..2ea19d28faa20 100644
--- a/src/Symfony/Component/Serializer/Extractor/ObjectPropertyListExtractor.php
+++ b/src/Symfony/Component/Serializer/Extractor/ObjectPropertyListExtractor.php
@@ -15,8 +15,10 @@
 
 /**
  * @author David Maicher <mail@dmaicher.de>
+ *
+ * @experimental in 4.3
  */
-class ObjectPropertyListExtractor implements ObjectPropertyListExtractorInterface
+final class ObjectPropertyListExtractor implements ObjectPropertyListExtractorInterface
 {
     private $propertyListExtractor;
     private $objectClassResolver;
diff --git a/src/Symfony/Component/Serializer/Extractor/ObjectPropertyListExtractorInterface.php b/src/Symfony/Component/Serializer/Extractor/ObjectPropertyListExtractorInterface.php
index 1dd9b8b99a7d3..fd60e1e5066f3 100644
--- a/src/Symfony/Component/Serializer/Extractor/ObjectPropertyListExtractorInterface.php
+++ b/src/Symfony/Component/Serializer/Extractor/ObjectPropertyListExtractorInterface.php
@@ -13,6 +13,8 @@
 
 /**
  * @author David Maicher <mail@dmaicher.de>
+ *
+ * @experimental in 4.3
  */
 interface ObjectPropertyListExtractorInterface
 {