diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2443671..ac69c61 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,7 +22,7 @@ jobs:
         extensions: bcmath, gmp, intl, dom, mbstring
 
     - name: Checkout code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Download dependencies
       run: composer update --prefer-stable --prefer-dist --no-interaction --no-progress --no-suggest --prefer-lowest --classmap-authoritative
@@ -38,6 +38,8 @@ jobs:
         php:
           - 8.1
           - 8.2
+          - 8.3
+          - 8.4
 
     steps:
     - name: Set up PHP
@@ -48,7 +50,10 @@ jobs:
         ini-values: zend.assertions=1
 
     - name: Checkout code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
+
+    - name: Remove psalm
+      run: composer remove psalm/plugin-phpunit psalm/plugin-symfony vimeo/psalm --dev
 
     - name: Validate composer.json and composer.lock
       run: composer validate --strict
@@ -74,7 +79,7 @@ jobs:
 
     steps:
     - name: Checkout code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Set up PHP
       uses: shivammathur/setup-php@v2
diff --git a/tests/DependencyInjection/MoneyExtensionTest.php b/tests/DependencyInjection/MoneyExtensionTest.php
index ccce4cc..67004ee 100644
--- a/tests/DependencyInjection/MoneyExtensionTest.php
+++ b/tests/DependencyInjection/MoneyExtensionTest.php
@@ -159,7 +159,7 @@ public function testMoneyDoctrineMapping(): void
      * @param array<class-string|string>                $publicServices
      * @param array<array-key, array<array-key, mixed>> $configs
      */
-    private function createContainer(array $publicServices = [], array $configs = [[]], \Closure $callback = null): ContainerInterface
+    private function createContainer(array $publicServices = [], array $configs = [[]], ?\Closure $callback = null): ContainerInterface
     {
         $parameters = [
             'kernel.debug' => true,