diff --git a/php/src/Google/Protobuf/Internal/Message.php b/php/src/Google/Protobuf/Internal/Message.php
index 14d660d89f..f412b419c8 100644
--- a/php/src/Google/Protobuf/Internal/Message.php
+++ b/php/src/Google/Protobuf/Internal/Message.php
@@ -54,6 +54,7 @@ use Google\Protobuf\NullValue;
  * or extend this class or its child classes by their own.  See the comment of
  * specific functions for more details.
  */
+#[\AllowDynamicProperties]
 class Message
 {