diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 0b29a0a..84565e2 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -29,6 +29,10 @@ jobs:
         php: ['8.3']
         mongodb: ['1.17.2']
         include:
+          - description: Tests - PHP 8.4
+            php: '8.4'
+            symfony-version: '7.*'
+            mongodb: '1.20.0' # 1.20 introduced PHP 8.4 support 
           - description: Tests - Symfony 6.4
             php: '8.2'
             symfony-version: '6.4.*'
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 397230f..df19c4d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## 1.4.1 (2024-12-09)
+* Add support to PHP 8.4 (by removing implicit nullable arguments deprecations)
+
 ## 1.4.0 (2024-03-15)
 * Allow Symfony 7 ([#18](https://github.com/facile-it/mongodb-messenger-transport/issues/18))
 * Require at least `facile-it/mongodb-bundle` 1.6
diff --git a/src/Transport/Connection.php b/src/Transport/Connection.php
index 93b2f69..03d21ab 100644
--- a/src/Transport/Connection.php
+++ b/src/Transport/Connection.php
@@ -179,7 +179,7 @@ public function find(string $id): ?BSONDocument
     /**
      * @return Cursor<BSONDocument>
      */
-    public function findAll(int $limit = null): Cursor
+    public function findAll(?int $limit = null): Cursor
     {
         $options = [];
         if ($limit !== null) {
diff --git a/src/Transport/MongoDbUnresettableTransport.php b/src/Transport/MongoDbUnresettableTransport.php
index 773f266..8afb794 100644
--- a/src/Transport/MongoDbUnresettableTransport.php
+++ b/src/Transport/MongoDbUnresettableTransport.php
@@ -62,7 +62,7 @@ public function send(Envelope $envelope): Envelope
      *
      * @return \Generator<Envelope>
      */
-    public function all(int $limit = null): iterable
+    public function all(?int $limit = null): iterable
     {
         return $this->getReceiver()->all($limit);
     }
diff --git a/src/Transport/Receiver.php b/src/Transport/Receiver.php
index a191a88..ea403bd 100644
--- a/src/Transport/Receiver.php
+++ b/src/Transport/Receiver.php
@@ -68,7 +68,7 @@ public function reject(Envelope $envelope): void
     /**
      * @return \Generator<Envelope>
      */
-    public function all(int $limit = null): iterable
+    public function all(?int $limit = null): iterable
     {
         foreach ($this->connection->findAll($limit) as $document) {
             yield $this->createEnvelope($document);
diff --git a/tests/Stubs/InstantiableDocumentEnhancer.php b/tests/Stubs/InstantiableDocumentEnhancer.php
index bef4893..4787ac1 100644
--- a/tests/Stubs/InstantiableDocumentEnhancer.php
+++ b/tests/Stubs/InstantiableDocumentEnhancer.php
@@ -13,7 +13,7 @@ class InstantiableDocumentEnhancer implements DocumentEnhancer
     /** @var \DateTime|null */
     private $foo;
 
-    public function __construct(\DateTime $foo = null)
+    public function __construct(?\DateTime $foo = null)
     {
         $this->foo = $foo;
     }
diff --git a/tests/Stubs/NotInstantiableDocumentEnhancer.php b/tests/Stubs/NotInstantiableDocumentEnhancer.php
index ed324ac..4cef559 100644
--- a/tests/Stubs/NotInstantiableDocumentEnhancer.php
+++ b/tests/Stubs/NotInstantiableDocumentEnhancer.php
@@ -10,7 +10,7 @@
 
 class NotInstantiableDocumentEnhancer implements DocumentEnhancer
 {
-    public function __construct(\DateTime $bar, \DateTime $foo = null) {}
+    public function __construct(\DateTime $bar, ?\DateTime $foo = null) {}
 
     public function enhance(BSONDocument $document, Envelope $envelope): void {}
 }