diff --git a/src/Adapter/MsgPack.php b/src/Adapter/MsgPack.php
index 08d0d42..c2ceb38 100644
--- a/src/Adapter/MsgPack.php
+++ b/src/Adapter/MsgPack.php
@@ -16,6 +16,9 @@
 use function msgpack_serialize;
 use function msgpack_unserialize;
 
+/**
+ * @deprecated This serializer will get removed in v3.0.0. There is no replacement.
+ */
 class MsgPack extends AbstractAdapter
 {
     /** @var string Serialized 0 value */
diff --git a/src/Adapter/PythonPickle.php b/src/Adapter/PythonPickle.php
index cf7b5a8..f786822 100644
--- a/src/Adapter/PythonPickle.php
+++ b/src/Adapter/PythonPickle.php
@@ -52,6 +52,7 @@
  * @link       http://pickle-js.googlecode.com
  * @see        Phython3.1/Lib/pickle.py
  * @see        Phython3.1/Modules/_pickle.c
+ * @deprecated This serializer will get removed in v3.0.0. There is no replacement.
  */
 class PythonPickle extends AbstractAdapter
 {
diff --git a/src/Adapter/PythonPickleOptions.php b/src/Adapter/PythonPickleOptions.php
index 9de38ea..f6426a3 100644
--- a/src/Adapter/PythonPickleOptions.php
+++ b/src/Adapter/PythonPickleOptions.php
@@ -10,6 +10,9 @@
 
 use Laminas\Serializer\Exception;
 
+/**
+ * @deprecated This serializer will get removed in v3.0.0. There is no replacement.
+ */
 class PythonPickleOptions extends AdapterOptions
 {
     /**
diff --git a/src/Adapter/Wddx.php b/src/Adapter/Wddx.php
index cc8f52a..6d11647 100644
--- a/src/Adapter/Wddx.php
+++ b/src/Adapter/Wddx.php
@@ -26,6 +26,7 @@
 /**
  * @link       http://www.infoloom.com/gcaconfs/WEB/chicago98/simeonov.HTM
  * @link       http://en.wikipedia.org/wiki/WDDX
+ * @deprecated This serializer will get removed in v3.0.0. There is no replacement.
  */
 class Wddx extends AbstractAdapter
 {
diff --git a/src/Adapter/WddxOptions.php b/src/Adapter/WddxOptions.php
index 1d35036..aec63ee 100644
--- a/src/Adapter/WddxOptions.php
+++ b/src/Adapter/WddxOptions.php
@@ -8,6 +8,9 @@
 
 namespace Laminas\Serializer\Adapter;
 
+/**
+ * @deprecated This serializer will get removed in v3.0.0. There is no replacement.
+ */
 class WddxOptions extends AdapterOptions
 {
     /**