diff --git a/CHANGELOG.md b/CHANGELOG.md
index 12c7fadb..8d16f050 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 ### Added
 ### Changed
+- Updated Client constructor to make EndpointFactory and optional parameter.
 ### Deprecated
 ### Removed
 ### Fixed
diff --git a/src/OpenSearch/Client.php b/src/OpenSearch/Client.php
index 8c105545..edaccc60 100644
--- a/src/OpenSearch/Client.php
+++ b/src/OpenSearch/Client.php
@@ -317,14 +317,14 @@ class Client
      * Client constructor
      *
      * @param TransportInterface|Transport $transport
-     * @param callable|EndpointFactoryInterface $endpointFactory
+     * @param callable|EndpointFactoryInterface|null $endpointFactory
      * @param NamespaceBuilderInterface[] $registeredNamespaces
      *
      * @phpstan-ignore parameter.deprecatedClass
      */
     public function __construct(
         TransportInterface|Transport $transport,
-        callable|EndpointFactoryInterface $endpointFactory,
+        callable|EndpointFactoryInterface|null $endpointFactory,
         array $registeredNamespaces = [],
     ) {
         if (!$transport instanceof TransportInterface) {
@@ -336,7 +336,9 @@ public function __construct(
         } else {
             $this->httpTransport = $transport;
         }
-        if (is_callable($endpointFactory)) {
+        if ($endpointFactory === null) {
+            $endpointFactory = new EndpointFactory();
+        } elseif (is_callable($endpointFactory)) {
             @trigger_error('Passing a callable as the $endpointFactory param in ' . __METHOD__ . ' is deprecated in 2.4.0 and will be removed in 3.0.0. Pass an instance of \OpenSearch\EndpointFactoryInterface instead.', E_USER_DEPRECATED);
             $endpoints = $endpointFactory;
             // @phpstan-ignore new.deprecated
diff --git a/util/template/client-class b/util/template/client-class
index b01e8f2a..d8b0d3e8 100644
--- a/util/template/client-class
+++ b/util/template/client-class
@@ -70,14 +70,14 @@ class Client
      * Client constructor
      *
      * @param TransportInterface|Transport $transport
-     * @param callable|EndpointFactoryInterface $endpointFactory
+     * @param callable|EndpointFactoryInterface|null $endpointFactory
      * @param NamespaceBuilderInterface[] $registeredNamespaces
      *
      * @phpstan-ignore parameter.deprecatedClass
      */
     public function __construct(
         TransportInterface|Transport $transport,
-        callable|EndpointFactoryInterface $endpointFactory,
+        callable|EndpointFactoryInterface|null $endpointFactory,
         array $registeredNamespaces = [],
     ) {
         if (!$transport instanceof TransportInterface) {
@@ -89,7 +89,9 @@ class Client
         } else {
             $this->httpTransport = $transport;
         }
-        if (is_callable($endpointFactory)) {
+        if ($endpointFactory === null) {
+            $endpointFactory = new EndpointFactory();
+        } elseif (is_callable($endpointFactory)) {
             @trigger_error('Passing a callable as the $endpointFactory param in ' . __METHOD__ . ' is deprecated in 2.4.0 and will be removed in 3.0.0. Pass an instance of \OpenSearch\EndpointFactoryInterface instead.', E_USER_DEPRECATED);
             $endpoints = $endpointFactory;
             // @phpstan-ignore new.deprecated