diff --git a/.gitignore b/.gitignore
index ff72e2d..8363287 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 /composer.lock
+/.phpunit.result.cache
 /vendor
diff --git a/Tests/DependencyInjection/KPhoenRulerZExtensionTest.php b/Tests/DependencyInjection/KPhoenRulerZExtensionTest.php
index 80fa669..7e419fd 100644
--- a/Tests/DependencyInjection/KPhoenRulerZExtensionTest.php
+++ b/Tests/DependencyInjection/KPhoenRulerZExtensionTest.php
@@ -18,7 +18,7 @@ class KPhoenRulerZExtensionTest extends AbstractExtensionTestCase
      */
     protected $root;
 
-    public function setUp()
+    protected function setUp(): void
     {
         parent::setUp();
 
@@ -26,12 +26,12 @@ public function setUp()
         $this->setParameter('kernel.debug', true);
     }
 
-    protected function getContainerExtensions()
+    protected function getContainerExtensions(): array
     {
         return [new KPhoenRulerZExtension()];
     }
 
-    protected function getMinimalConfiguration()
+    protected function getMinimalConfiguration(): array
     {
         return [
             'cache' => $this->root->url().'/cache',
diff --git a/composer.json b/composer.json
index 739695d..d2e9761 100644
--- a/composer.json
+++ b/composer.json
@@ -24,10 +24,10 @@
         "symfony/framework-bundle": "^4.4"
     },
     "require-dev": {
-        "phpunit/phpunit": "^7.1",
+        "phpunit/phpunit": "^8.5.16",
         "symfony/phpunit-bridge": "^4.4",
         "mikey179/vfsstream": "^1.6",
-        "matthiasnoback/symfony-dependency-injection-test": "^3.0",
+        "matthiasnoback/symfony-dependency-injection-test": "^4.0",
         "liip/rmt": "^1.2"
     }
 }