diff --git a/DataCollector/ProfilerDataCollector.php b/DataCollector/ProfilerDataCollector.php
index 69fc0f9..5dc6e55 100644
--- a/DataCollector/ProfilerDataCollector.php
+++ b/DataCollector/ProfilerDataCollector.php
@@ -15,6 +15,7 @@
 use Symfony\Component\Serializer\Serializer;
 use Symfony\Component\Serializer\Encoder\JsonEncoder;
 use Symfony\Component\Stopwatch\Stopwatch;
+use Throwable;
 
 /*
  * @author Emmanuel VAISSE
@@ -53,7 +54,7 @@ public function __construct(protected bool $debug)
     {
     }
 
-    public function collect(Request $request, Response $response, \Throwable $exception = null): void
+    public function collect(Request $request, Response $response, ?Throwable $exception = null): void
     {
         $this->data = array(
             'countRequests'              => count($this->calls),
@@ -332,7 +333,7 @@ public function fetchResponseInfos(Response $response): array
         return $data;
     }
 
-    public function fetchErrorInfos(\Throwable $error): array
+    public function fetchErrorInfos(Throwable $error): array
     {
         return [
             'class'         => get_class($error),
diff --git a/Http/Exception/BadGatewayHttpException.php b/Http/Exception/BadGatewayHttpException.php
index 767c39a..34d72bb 100644
--- a/Http/Exception/BadGatewayHttpException.php
+++ b/Http/Exception/BadGatewayHttpException.php
@@ -9,6 +9,8 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class BadGatewayHttpException extends ServerErrorHttpException
 {
 
@@ -16,10 +18,10 @@ class BadGatewayHttpException extends ServerErrorHttpException
      * Constructor.
      *
      * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param Exception|null $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(502, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/ExpectationFailedHttpException.php b/Http/Exception/ExpectationFailedHttpException.php
index 67bea85..e4e2301 100644
--- a/Http/Exception/ExpectationFailedHttpException.php
+++ b/Http/Exception/ExpectationFailedHttpException.php
@@ -9,17 +9,19 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class ExpectationFailedHttpException extends ClientErrorHttpException
 {
 
     /**
      * Constructor.
      *
-     * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param string|null     $message   The internal exception message
+     * @param Exception|null $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(417, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/ForbiddenHttpException.php b/Http/Exception/ForbiddenHttpException.php
index fbc1c7e..438dc56 100644
--- a/Http/Exception/ForbiddenHttpException.php
+++ b/Http/Exception/ForbiddenHttpException.php
@@ -9,16 +9,18 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class ForbiddenHttpException extends ClientErrorHttpException
 {
     /**
      * Constructor.
      *
      * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param Exception|null $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(403, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/GatewayTimeoutHttpException.php b/Http/Exception/GatewayTimeoutHttpException.php
index 1ec8a90..0642c12 100644
--- a/Http/Exception/GatewayTimeoutHttpException.php
+++ b/Http/Exception/GatewayTimeoutHttpException.php
@@ -9,6 +9,8 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class GatewayTimeoutHttpException extends ServerErrorHttpException
 {
 
@@ -16,10 +18,10 @@ class GatewayTimeoutHttpException extends ServerErrorHttpException
      * Constructor.
      *
      * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param Exception|null $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(504, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/HttpVersionNotSupportedHttpException.php b/Http/Exception/HttpVersionNotSupportedHttpException.php
index 059a0f2..7b17216 100644
--- a/Http/Exception/HttpVersionNotSupportedHttpException.php
+++ b/Http/Exception/HttpVersionNotSupportedHttpException.php
@@ -9,16 +9,18 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class HttpVersionNotSupportedHttpException extends ServerErrorHttpException
 {
     /**
      * Constructor.
      *
      * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param Exception|null $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(505, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/InternalServerErrorHttpException.php b/Http/Exception/InternalServerErrorHttpException.php
index 0afe47d..daab496 100644
--- a/Http/Exception/InternalServerErrorHttpException.php
+++ b/Http/Exception/InternalServerErrorHttpException.php
@@ -9,6 +9,8 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class InternalServerErrorHttpException extends ServerErrorHttpException
 {
 
@@ -16,10 +18,10 @@ class InternalServerErrorHttpException extends ServerErrorHttpException
      * Constructor.
      *
      * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param Exception|null $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(500, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/NotImplementedHttpException.php b/Http/Exception/NotImplementedHttpException.php
index fab8609..be63544 100644
--- a/Http/Exception/NotImplementedHttpException.php
+++ b/Http/Exception/NotImplementedHttpException.php
@@ -9,6 +9,8 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class NotImplementedHttpException extends ServerErrorHttpException
 {
 
@@ -16,10 +18,10 @@ class NotImplementedHttpException extends ServerErrorHttpException
      * Constructor.
      *
      * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param Exception|null $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(501, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/ProxyAuthenticationRequiredHttpException.php b/Http/Exception/ProxyAuthenticationRequiredHttpException.php
index 76b349c..2f7be2a 100644
--- a/Http/Exception/ProxyAuthenticationRequiredHttpException.php
+++ b/Http/Exception/ProxyAuthenticationRequiredHttpException.php
@@ -9,6 +9,8 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class ProxyAuthenticationRequiredHttpException extends ClientErrorHttpException
 {
 
@@ -16,10 +18,10 @@ class ProxyAuthenticationRequiredHttpException extends ClientErrorHttpException
      * Constructor.
      *
      * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param Exception|null $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(407, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/RequestEntityTooLargeHttpException.php b/Http/Exception/RequestEntityTooLargeHttpException.php
index dc61272..f5f97fe 100644
--- a/Http/Exception/RequestEntityTooLargeHttpException.php
+++ b/Http/Exception/RequestEntityTooLargeHttpException.php
@@ -9,6 +9,8 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class RequestEntityTooLargeHttpException extends ClientErrorHttpException
 {
 
@@ -16,10 +18,10 @@ class RequestEntityTooLargeHttpException extends ClientErrorHttpException
      * Constructor.
      *
      * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param Exception|null $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(413, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/RequestTimeoutHttpException.php b/Http/Exception/RequestTimeoutHttpException.php
index e83ec5e..748fd7a 100644
--- a/Http/Exception/RequestTimeoutHttpException.php
+++ b/Http/Exception/RequestTimeoutHttpException.php
@@ -9,6 +9,8 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class RequestTimeoutHttpException extends ClientErrorHttpException
 {
 
@@ -16,10 +18,10 @@ class RequestTimeoutHttpException extends ClientErrorHttpException
      * Constructor.
      *
      * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param Exception $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(408, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/RequestUriTooLongHttpException.php b/Http/Exception/RequestUriTooLongHttpException.php
index 5569ade..a8ee205 100644
--- a/Http/Exception/RequestUriTooLongHttpException.php
+++ b/Http/Exception/RequestUriTooLongHttpException.php
@@ -9,16 +9,18 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class RequestUriTooLongHttpException extends ClientErrorHttpException {
 
     /**
      * Constructor.
      *
      * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param Exception|null $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(414, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/RequestedRangeNotSatisfiableHttpException.php b/Http/Exception/RequestedRangeNotSatisfiableHttpException.php
index b33a459..e8e2a15 100644
--- a/Http/Exception/RequestedRangeNotSatisfiableHttpException.php
+++ b/Http/Exception/RequestedRangeNotSatisfiableHttpException.php
@@ -9,6 +9,8 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 
+use Exception;
+
 class RequestedRangeNotSatisfiableHttpException extends ClientErrorHttpException
 {
 
@@ -16,10 +18,10 @@ class RequestedRangeNotSatisfiableHttpException extends ClientErrorHttpException
      * Constructor.
      *
      * @param string     $message   The internal exception message
-     * @param \Exception $previous  The previous exception
+     * @param Exception|null $previous  The previous exception
      * @param int        $code      The internal exception code
      */
-    public function __construct($message = null, \Exception $previous = null, $code = 0)
+    public function __construct($message = null, ?Exception $previous = null, $code = 0)
     {
         parent::__construct(416, $message, $previous, array(), $code);
     }
diff --git a/Http/Exception/ResponseException.php b/Http/Exception/ResponseException.php
index b2942fc..e787e3f 100644
--- a/Http/Exception/ResponseException.php
+++ b/Http/Exception/ResponseException.php
@@ -9,6 +9,7 @@
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
 use evaisse\SimpleHttpBundle\Http\Response;
+use Exception;
 use Symfony\Component\HttpKernel\Exception\HttpException;
 
 
@@ -30,9 +31,9 @@ class ResponseException extends HttpException
      * @param Response $response response attached to error
      * @param string $message Message describing exception
      * @param int $code error code
-     * @param \Exception $previous optionnal previous exception
+     * @param Exception|null $previous optionnal previous exception
      */
-    public function __construct(Response $response, $message = "", $code = 0, \Exception $previous = null)
+    public function __construct(Response $response, $message = "", $code = 0, ?Exception $previous = null)
     {
         parent::__construct(580, $message, $previous, [], $code); // TODO: Change the autogenerated stub
         $this->setResponse($response);
diff --git a/Http/Exception/TransportException.php b/Http/Exception/TransportException.php
index 72b7ff8..62a48f3 100644
--- a/Http/Exception/TransportException.php
+++ b/Http/Exception/TransportException.php
@@ -2,7 +2,7 @@
 
 namespace evaisse\SimpleHttpBundle\Http\Exception;
 
-use evaisse\SimpleHttpBundle\Http\Exception;
+use Exception;
 use Symfony\Component\HttpKernel\Exception\HttpException;
 
 abstract class TransportException extends HttpException
@@ -11,9 +11,9 @@ abstract class TransportException extends HttpException
     /**
      * @param string $message
      * @param int $code
-     * @param \Exception $previous
+     * @param Exception|null $previous
      */
-    public function __construct($message = null, $code = 0, \Exception $previous = null)
+    public function __construct($message = null, $code = 0, ?Exception $previous = null)
     {
         /*
          * @see https://en.wikipedia.org/wiki/List_of_HTTP_status_codes
diff --git a/Http/Kernel.php b/Http/Kernel.php
index b3c6551..7afd925 100644
--- a/Http/Kernel.php
+++ b/Http/Kernel.php
@@ -71,7 +71,7 @@ class Kernel extends RemoteHttpKernel
      * @param EventDispatcherInterface $eventDispatcher
      * @param RequestGenerator|null $generator Optionnal generator to construct curlrequest
      */
-    public function __construct(EventDispatcherInterface $eventDispatcher, RequestGenerator $generator = null)
+    public function __construct(EventDispatcherInterface $eventDispatcher, ?RequestGenerator $generator = null)
     {
         $this->setEventDispatcher($eventDispatcher);
         parent::__construct($generator);
@@ -354,13 +354,13 @@ protected function prepareRawCurlHandler(Statement $stmt): array
      *
      * @param string $filename realpath to file
      * @param string $mimetype mime content type
-     * @param string $postname base name for file
+     * @param string|null $postname base name for file
      *
      * @throws \InvalidArgumentException
      *
      * @return mixed|string|CURLFile if version >= 5.5, CURLFile instance will be return, otherwise a string resource
      */
-    protected function createCurlFile(string $filename, string $mimetype, string $postname = null): mixed
+    protected function createCurlFile(string $filename, string $mimetype, ?string $postname = null): mixed
     {
         if (!realpath($filename) && is_file($filename)) {
             throw new \InvalidArgumentException('invalid given filepath : ' . $filename);
diff --git a/Http/Kernel/RemoteHttpKernel.php b/Http/Kernel/RemoteHttpKernel.php
index c135291..89b2ea9 100644
--- a/Http/Kernel/RemoteHttpKernel.php
+++ b/Http/Kernel/RemoteHttpKernel.php
@@ -37,7 +37,7 @@ class RemoteHttpKernel implements HttpKernelInterface
 
     private $lastCurlRequest;
 
-    public function __construct(RequestGenerator $generator = null)
+    public function __construct(?RequestGenerator $generator = null)
     {
         $this->generator = $generator;
     }
diff --git a/Http/SessionCookieJar.php b/Http/SessionCookieJar.php
index f2c9629..100f318 100644
--- a/Http/SessionCookieJar.php
+++ b/Http/SessionCookieJar.php
@@ -32,7 +32,7 @@ class SessionCookieJar extends CookieJar
      * @param SessionInterface $session Session storage to persist cookieJar
      * @param string $cookieJarName A key in which will be stored the cookie jar
      */
-    function __construct(SessionInterface $session = null, $cookieJarName = "_simple_http.cookiejar")
+    function __construct(?SessionInterface $session = null, $cookieJarName = "_simple_http.cookiejar")
     {
         $session = $session ? $session : new Session(new MockArraySessionStorage());
         $this->setSession($session);
diff --git a/Http/Statement.php b/Http/Statement.php
index b794a8d..ecaf69f 100644
--- a/Http/Statement.php
+++ b/Http/Statement.php
@@ -127,7 +127,7 @@ public function setHttpKernel(Kernel $httpKernel): void
      *
      * @param Request $request An http request object to send
      */
-    public function __construct(Request $request, EventDispatcherInterface $eventDispatcher, Kernel $httpKernel = null)
+    public function __construct(Request $request, EventDispatcherInterface $eventDispatcher, ?Kernel $httpKernel = null)
     {
         $this->setRequest($request);
         $this->deferred = new Deferred();
@@ -327,7 +327,7 @@ public function getUid()
      * @throws Error
      * @throws Exception
      */
-    public function execute(Kernel $httpKernel = null)
+    public function execute(?Kernel $httpKernel = null)
     {
         $this->sent = true;
         $http = $httpKernel ? $httpKernel : $this->httpKernel;
diff --git a/Serializer/CustomGetSetNormalizer.php b/Serializer/CustomGetSetNormalizer.php
index d74eeec..faf15e6 100644
--- a/Serializer/CustomGetSetNormalizer.php
+++ b/Serializer/CustomGetSetNormalizer.php
@@ -15,7 +15,7 @@ class CustomGetSetNormalizer extends GetSetMethodNormalizer
     /**
      * {@inheritdoc}
      */
-    public function normalize(mixed $object, string $format = null, array $context = [])
+    public function normalize(mixed $object, ?string $format = null, array $context = [])
     {
         if ($object instanceof \Throwable) {
             return $this->normalizeThrowable($object);
diff --git a/Serializer/RequestNormalizer.php b/Serializer/RequestNormalizer.php
index 8ce0020..7dfe5dd 100644
--- a/Serializer/RequestNormalizer.php
+++ b/Serializer/RequestNormalizer.php
@@ -7,7 +7,7 @@
 
 class RequestNormalizer extends GetSetMethodNormalizer
 {
-    protected function getAttributeValue(object $object, string $attribute, string $format = null, array $context = []): mixed
+    protected function getAttributeValue(object $object, string $attribute, ?string $format = null, array $context = []): mixed
     {
         $ucfirsted = ucfirst($attribute);
 
diff --git a/Service/Helper.php b/Service/Helper.php
index 328f544..d352b59 100644
--- a/Service/Helper.php
+++ b/Service/Helper.php
@@ -41,10 +41,10 @@ public function getDefaultCookieJar(): SessionCookieJar|CookieJar
     }
 
     /**
-     * @param SessionInterface $session session to store the cookies
+     * @param SessionInterface|null $session session to store the cookies
      * @return SessionCookieJar
      */
-    public function createCookieJar(SessionInterface $session = null): SessionCookieJar
+    public function createCookieJar(?SessionInterface $session = null): SessionCookieJar
     {
         return new SessionCookieJar($session);
     }
@@ -58,7 +58,7 @@ public function createCookieJar(SessionInterface $session = null): SessionCookie
      * @param Kernel|null $client http client proxy to use
      * @return Helper given service list
      */
-    public function execute(array $servicesList, SessionCookieJar $cookieJar = null, Kernel $client = null): static
+    public function execute(array $servicesList, ?SessionCookieJar $cookieJar = null, Kernel $client = null): static
     {
         $httpClient = $client ? $client : $this->httpKernel;