diff --git a/.github/workflows/analyzers.yaml b/.github/workflows/analyzers.yaml
index b67d45e..8670bcf 100644
--- a/.github/workflows/analyzers.yaml
+++ b/.github/workflows/analyzers.yaml
@@ -7,7 +7,8 @@ jobs:
         strategy:
             matrix:
                 operating-system: [ubuntu-latest]
-                php-versions: ['8.1', '8.2', '8.3']
+                php-versions: ['8.2', '8.3', '8.4']
+                composer-options: ['--ignore-platform-req=php+']
             fail-fast: false
         name: PHP ${{ matrix.php-versions }} @ ${{ matrix.operating-system }}
         steps:
diff --git a/.github/workflows/code-style.yaml b/.github/workflows/code-style.yaml
index 089eaa5..a8a0975 100644
--- a/.github/workflows/code-style.yaml
+++ b/.github/workflows/code-style.yaml
@@ -7,7 +7,8 @@ jobs:
         strategy:
             matrix:
                 operating-system: [ubuntu-latest]
-                php-versions: ['8.1', '8.2', '8.3']
+                php-versions: ['8.2', '8.3', '8.4']
+                composer-options: ['--ignore-platform-req=php+']
             fail-fast: false
         name: PHP ${{ matrix.php-versions }} @ ${{ matrix.operating-system }}
         steps:
diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 7970d91..b471eec 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -7,7 +7,8 @@ jobs:
         strategy:
             matrix:
                 operating-system: [ubuntu-latest]
-                php-versions: ['8.1', '8.2', '8.3']
+                php-versions: ['8.2', '8.3', '8.4']
+                composer-options: ['--ignore-platform-req=php+']
             fail-fast: false
         name: PHP ${{ matrix.php-versions }} @ ${{ matrix.operating-system }}
         steps:
@@ -20,6 +21,6 @@ jobs:
                   tools: 'composer:v2'
                   extensions: pcov, mbstring, posix, dom, soap
             - name: Install dependencies
-              run: composer update --prefer-dist --no-progress --no-suggest
+              run: composer update --prefer-dist --no-progress --no-suggest ${{ matrix.composer-options }}
             - name: Run the tests
               run: ./vendor/bin/phpunit
diff --git a/.phive/phars.xml b/.phive/phars.xml
index 322a41f..4aa93da 100644
--- a/.phive/phars.xml
+++ b/.phive/phars.xml
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phive xmlns="https://phar.io/phive">
-  <phar name="php-cs-fixer" version="^3.13.0" installed="3.39.0" location="./tools/php-cs-fixer.phar" copy="true"/>
+  <phar name="php-cs-fixer" version="^3.13.0" installed="3.64.0" location="./tools/php-cs-fixer.phar" copy="true"/>
 </phive>
diff --git a/.php-cs-fixer.dist.php b/.php-cs-fixer.dist.php
index b2fc9eb..7faf356 100644
--- a/.php-cs-fixer.dist.php
+++ b/.php-cs-fixer.dist.php
@@ -53,5 +53,6 @@
         'static_lambda' => true,
         'strict_comparison' => true,
         'strict_param' => true,
+        'nullable_type_declaration_for_default_null_value' => true,
     ])
 ;
diff --git a/composer.json b/composer.json
index 69de947..7db5d74 100644
--- a/composer.json
+++ b/composer.json
@@ -15,9 +15,9 @@
         }
     ],
     "require": {
-        "php": "~8.1.0 || ~8.2.0 || ~8.3.0",
-        "azjezz/psl": "^2.5",
-        "php-soap/xml": "^1.6.0"
+        "php": "~8.2.0 || ~8.3.0 || ~8.4.0",
+        "azjezz/psl": "^3.0",
+        "php-soap/xml": "^1.8.0"
     },
     "autoload-dev": {
         "psr-4": {
@@ -25,8 +25,8 @@
         }
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.5",
+        "phpunit/phpunit": "^10.5",
         "php-standard-library/psalm-plugin": "^2.2",
-        "vimeo/psalm": "^5.9"
+        "vimeo/psalm": "^5.26"
     }
 }
diff --git a/phpunit.xml b/phpunit.xml
index 63f65e9..9b20708 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,4 +1,9 @@
-<phpunit bootstrap="./vendor/autoload.php" colors="true">
+<phpunit
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
+        displayDetailsOnPhpunitDeprecations="true"
+        bootstrap="./vendor/autoload.php"
+        colors="true">
     <testsuites>
         <testsuite name="Unit">
             <directory>./tests/Unit</directory>
diff --git a/src/Exception/RuntimeException.php b/src/Exception/RuntimeException.php
index a2ddd7e..603bc4a 100644
--- a/src/Exception/RuntimeException.php
+++ b/src/Exception/RuntimeException.php
@@ -8,7 +8,7 @@
 
 abstract class RuntimeException extends \RuntimeException
 {
-    protected function __construct(string $message = "", int $code = 0, Throwable $previous = null)
+    protected function __construct(string $message = "", int $code = 0, ?Throwable $previous = null)
     {
         parent::__construct($message, $code, $previous);
     }
diff --git a/tools/php-cs-fixer.phar b/tools/php-cs-fixer.phar
index 9a03f3e..d071fa5 100755
Binary files a/tools/php-cs-fixer.phar and b/tools/php-cs-fixer.phar differ