diff --git a/src/Symfony/Component/Validator/Constraints/Composite.php b/src/Symfony/Component/Validator/Constraints/Composite.php
index 18ea5e319f7f1..9c72a57572a43 100644
--- a/src/Symfony/Component/Validator/Constraints/Composite.php
+++ b/src/Symfony/Component/Validator/Constraints/Composite.php
@@ -25,6 +25,8 @@
  * contains the nested constraints.
  *
  * @author Bernhard Schussek <bschussek@gmail.com>
+ *
+ * @internal since Symfony 5.1
  */
 abstract class Composite extends Constraint
 {