diff --git a/src/OpenSearch/Helper/Iterators/SearchHitIterator.php b/src/OpenSearch/Helper/Iterators/SearchHitIterator.php
index 84ca74630..aa00504f8 100644
--- a/src/OpenSearch/Helper/Iterators/SearchHitIterator.php
+++ b/src/OpenSearch/Helper/Iterators/SearchHitIterator.php
@@ -23,6 +23,12 @@
 
 use Iterator;
 
+// @phpstan-ignore classConstant.deprecatedClass
+@trigger_error(SearchHitIterator::class . ' is deprecated in 2.4.0 and will be removed in 3.0.0.', E_USER_DEPRECATED);
+
+/**
+ * @deprecated in 2.4.0 and will be removed in 3.0.0.
+ */
 class SearchHitIterator implements Iterator, \Countable
 {
     /**
diff --git a/src/OpenSearch/Helper/Iterators/SearchResponseIterator.php b/src/OpenSearch/Helper/Iterators/SearchResponseIterator.php
index ec6e8e5d8..7d605ca77 100644
--- a/src/OpenSearch/Helper/Iterators/SearchResponseIterator.php
+++ b/src/OpenSearch/Helper/Iterators/SearchResponseIterator.php
@@ -24,6 +24,12 @@
 use OpenSearch\Client;
 use Iterator;
 
+// @phpstan-ignore classConstant.deprecatedClass
+@trigger_error(SearchResponseIterator::class . ' is deprecated in 2.4.0 and will be removed in 3.0.0.', E_USER_DEPRECATED);
+
+/**
+ * @deprecated in 2.4.0 and will be removed in 3.0.0.
+ */
 class SearchResponseIterator implements Iterator
 {
     /**
diff --git a/src/OpenSearch/Serializers/ArrayToJSONSerializer.php b/src/OpenSearch/Serializers/ArrayToJSONSerializer.php
index de119fa58..6237258fa 100644
--- a/src/OpenSearch/Serializers/ArrayToJSONSerializer.php
+++ b/src/OpenSearch/Serializers/ArrayToJSONSerializer.php
@@ -23,11 +23,17 @@
 
 use OpenSearch\Common\Exceptions\RuntimeException;
 
+// @phpstan-ignore classConstant.deprecatedClass
+@trigger_error(ArrayToJSONSerializer::class . ' is deprecated in 2.4.0 and will be removed in 3.0.0.', E_USER_DEPRECATED);
+
 if (!defined('JSON_INVALID_UTF8_SUBSTITUTE')) {
     //PHP < 7.2 Define it as 0 so it does nothing
     define('JSON_INVALID_UTF8_SUBSTITUTE', 0);
 }
 
+/**
+ * @deprecated in 2.4.0 and will be removed in 3.0.0.
+ */
 class ArrayToJSONSerializer implements SerializerInterface
 {
     /**
diff --git a/src/OpenSearch/Serializers/EverythingToJSONSerializer.php b/src/OpenSearch/Serializers/EverythingToJSONSerializer.php
index fc1c40515..e0f1359e2 100644
--- a/src/OpenSearch/Serializers/EverythingToJSONSerializer.php
+++ b/src/OpenSearch/Serializers/EverythingToJSONSerializer.php
@@ -23,11 +23,17 @@
 
 use OpenSearch\Common\Exceptions\RuntimeException;
 
+// @phpstan-ignore classConstant.deprecatedClass
+@trigger_error(EverythingToJSONSerializer::class . ' is deprecated in 2.4.0 and will be removed in 3.0.0.', E_USER_DEPRECATED);
+
 if (!defined('JSON_INVALID_UTF8_SUBSTITUTE')) {
     //PHP < 7.2 Define it as 0 so it does nothing
     define('JSON_INVALID_UTF8_SUBSTITUTE', 0);
 }
 
+/**
+ * @deprecated in 2.4.0 and will be removed in 3.0.0.
+ */
 class EverythingToJSONSerializer implements SerializerInterface
 {
     /**
diff --git a/tests/ClientBuilder/ArrayLogger.php b/tests/ClientBuilder/ArrayLogger.php
index 68640be90..04edb9875 100644
--- a/tests/ClientBuilder/ArrayLogger.php
+++ b/tests/ClientBuilder/ArrayLogger.php
@@ -25,6 +25,12 @@
 use Psr\Log\LoggerInterface;
 use Psr\Log\LogLevel;
 
+// @phpstan-ignore classConstant.deprecatedClass
+@trigger_error(ArrayLogger::class . ' is deprecated in 2.4.0 and will be removed in 3.0.0.', E_USER_DEPRECATED);
+
+/**
+ * @deprecated in 2.4.0 and will be removed in 3.0.0.
+ */
 class ArrayLogger implements LoggerInterface
 {
     /**
diff --git a/tests/Helper/Iterators/SearchHitIteratorTest.php b/tests/Helper/Iterators/SearchHitIteratorTest.php
index 080e5d1fa..406d7e657 100644
--- a/tests/Helper/Iterators/SearchHitIteratorTest.php
+++ b/tests/Helper/Iterators/SearchHitIteratorTest.php
@@ -28,6 +28,7 @@
 /**
  * Class SearchResponseIteratorTest
  *
+ * @deprecated in 2.4.0 and will be removed in 3.0.0.
  */
 class SearchHitIteratorTest extends \PHPUnit\Framework\TestCase
 {
diff --git a/tests/Helper/Iterators/SearchResponseIteratorTest.php b/tests/Helper/Iterators/SearchResponseIteratorTest.php
index e971278cb..b5473caca 100644
--- a/tests/Helper/Iterators/SearchResponseIteratorTest.php
+++ b/tests/Helper/Iterators/SearchResponseIteratorTest.php
@@ -28,6 +28,7 @@
 /**
  * Class SearchResponseIteratorTest
  *
+ * @deprecated in 2.4.0 and will be removed in 3.0.0.
  */
 class SearchResponseIteratorTest extends \PHPUnit\Framework\TestCase
 {
diff --git a/tests/Serializers/ArrayToJSONSerializerTest.php b/tests/Serializers/ArrayToJSONSerializerTest.php
index 1b2b0630b..c3b0a7daa 100644
--- a/tests/Serializers/ArrayToJSONSerializerTest.php
+++ b/tests/Serializers/ArrayToJSONSerializerTest.php
@@ -27,6 +27,7 @@
 /**
  * Class ArrayToJSONSerializerTest
  *
+ * @deprecated in 2.4.0 and will be removed in 3.0.0.
  */
 class ArrayToJSONSerializerTest extends \PHPUnit\Framework\TestCase
 {
diff --git a/tests/Serializers/EverythingToJSONSerializerTest.php b/tests/Serializers/EverythingToJSONSerializerTest.php
index 93b7c5d5f..137c5caa3 100644
--- a/tests/Serializers/EverythingToJSONSerializerTest.php
+++ b/tests/Serializers/EverythingToJSONSerializerTest.php
@@ -27,6 +27,7 @@
 /**
  * Class EverythingToJSONSerializerTest
  *
+ * @deprecated in 2.4.0 and will be removed in 3.0.0.
  */
 class EverythingToJSONSerializerTest extends \PHPUnit\Framework\TestCase
 {