diff --git a/UPGRADE-3.4.md b/UPGRADE-3.4.md
index 5408251e98968..f72652fbe4715 100644
--- a/UPGRADE-3.4.md
+++ b/UPGRADE-3.4.md
@@ -203,6 +203,8 @@ Validator
 Yaml
 ----
 
+ * the `Dumper`, `Parser`, and `Yaml` classes are marked as final
+
  * using the `!php/object:` tag is deprecated and won't be supported in 4.0. Use
    the `!php/object` tag (without the colon) instead.
 
diff --git a/src/Symfony/Component/Yaml/CHANGELOG.md b/src/Symfony/Component/Yaml/CHANGELOG.md
index bdbac2b93e917..cdd49352d5185 100644
--- a/src/Symfony/Component/Yaml/CHANGELOG.md
+++ b/src/Symfony/Component/Yaml/CHANGELOG.md
@@ -4,6 +4,8 @@ CHANGELOG
 3.4.0
 -----
 
+ * the `Dumper`, `Parser`, and `Yaml` classes are marked as final
+
  * Deprecated the `!php/object:` tag which will be replaced by the
    `!php/object` tag (without the colon) in 4.0.
 
diff --git a/src/Symfony/Component/Yaml/Dumper.php b/src/Symfony/Component/Yaml/Dumper.php
index e26a65a5076d7..427f1a7b0f7d6 100644
--- a/src/Symfony/Component/Yaml/Dumper.php
+++ b/src/Symfony/Component/Yaml/Dumper.php
@@ -15,6 +15,8 @@
  * Dumper dumps PHP variables to YAML strings.
  *
  * @author Fabien Potencier <fabien@symfony.com>
+ *
+ * @final since version 3.4
  */
 class Dumper
 {
diff --git a/src/Symfony/Component/Yaml/Parser.php b/src/Symfony/Component/Yaml/Parser.php
index 1ebd958482e88..b39512c869d14 100644
--- a/src/Symfony/Component/Yaml/Parser.php
+++ b/src/Symfony/Component/Yaml/Parser.php
@@ -18,6 +18,8 @@
  * Parser parses YAML strings to convert them to PHP arrays.
  *
  * @author Fabien Potencier <fabien@symfony.com>
+ *
+ * @final since version 3.4
  */
 class Parser
 {
diff --git a/src/Symfony/Component/Yaml/Yaml.php b/src/Symfony/Component/Yaml/Yaml.php
index 82397fbcb5172..52a064f70b5fb 100644
--- a/src/Symfony/Component/Yaml/Yaml.php
+++ b/src/Symfony/Component/Yaml/Yaml.php
@@ -17,6 +17,8 @@
  * Yaml offers convenience methods to load and dump YAML.
  *
  * @author Fabien Potencier <fabien@symfony.com>
+ *
+ * @final since version 3.4
  */
 class Yaml
 {