diff --git a/.github/workflows/main.yaml b/.github/workflows/main.yaml
index 6a0941d..ef231df 100644
--- a/.github/workflows/main.yaml
+++ b/.github/workflows/main.yaml
@@ -8,7 +8,7 @@ jobs:
 
         strategy:
             matrix:
-                php-versions: ['7.3', '7.4', '8.0']
+                php-versions: ['8.1','8.2','8.3']
         name: PHP ${{ matrix.php-versions }}
         steps:
             -   uses: actions/checkout@v2
diff --git a/composer.json b/composer.json
index c584589..6d9b245 100644
--- a/composer.json
+++ b/composer.json
@@ -5,20 +5,20 @@
     "license":           "MIT",
     "minimum-stability": "dev",
     "require": {
-        "php":                          ">=7.3",
+        "php":                          "^8.1",
         "doctrine/annotations":         "^1.3",
-        "symfony/config":               "^4.4|^5.0",
-        "symfony/dependency-injection": "^4.4|^5.0",
-        "symfony/framework-bundle":     "^4.4|^5.0",
-        "symfony/http-kernel":          "^4.4|^5.0",
-        "symfony/routing":              "^4.4|^5.0",
-        "symfony/translation":          "^4.4|^5.0",
-        "symfony/yaml":                 "^4.4|^5.0"
+        "symfony/config":               "^5.4|^6.0",
+        "symfony/dependency-injection": "^5.4|^6.0",
+        "symfony/framework-bundle":     "^5.4|^6.0",
+        "symfony/http-kernel":          "^5.4|^6.0",
+        "symfony/routing":              "^5.4|^6.0",
+        "symfony/translation":          "^5.4|^6.0",
+        "symfony/yaml":                 "^5.4|^6.0"
     },
     "require-dev": {
         "hostnet/phpcs-tool": "^9.1.0",
         "phpunit/phpunit":    "^9.5.6",
-        "symfony/finder":     "^5.0"
+        "symfony/finder":     "^5.4|^6.0"
     },
     "autoload": {
         "psr-4": {
diff --git a/src/Loader/EnumLoader.php b/src/Loader/EnumLoader.php
index c01aa36..620b3aa 100644
--- a/src/Loader/EnumLoader.php
+++ b/src/Loader/EnumLoader.php
@@ -35,7 +35,7 @@ public function __construct(YamlFileLoader $yml_loader)
     /**
      * {@inheritdoc}
      */
-    public function load($resource, $locale, $domain = 'messages')
+    public function load($resource, $locale, $domain = 'messages'): MessageCatalogue
     {
         if (!class_exists($domain)) {
             throw new \RuntimeException(sprintf("Could not load constants for a class '%s'.", $domain));
diff --git a/test/Functional/Fixtures/TestKernel.php b/test/Functional/Fixtures/TestKernel.php
index 49a10ff..f4dc082 100644
--- a/test/Functional/Fixtures/TestKernel.php
+++ b/test/Functional/Fixtures/TestKernel.php
@@ -12,7 +12,7 @@ class TestKernel extends Kernel
     /**
      * {@inheritdoc}
      */
-    public function registerBundles()
+    public function registerBundles(): iterable
     {
         return [
             new Symfony\Bundle\FrameworkBundle\FrameworkBundle(),
@@ -29,12 +29,12 @@ public function registerContainerConfiguration(LoaderInterface $loader)
         $loader->load(__DIR__ . '/config/config.yml');
     }
 
-    public function getCacheDir()
+    public function getCacheDir(): string
     {
         return dirname(__DIR__) . '/../../var/cache';
     }
 
-    public function getLogDir()
+    public function getLogDir(): string
     {
         return dirname(__DIR__) . '/../../var/logs';
     }