diff --git a/composer.json b/composer.json
index 5b6ef78..09352ac 100644
--- a/composer.json
+++ b/composer.json
@@ -17,11 +17,11 @@
 		"symfony/http-kernel": "^7.2"
 	},
 	"require-dev": {
-		"21torr/janus": "^1.4",
-		"bamarni/composer-bin-plugin": "^1.8",
+		"21torr/janus": "^1.5.1",
+		"bamarni/composer-bin-plugin": "^1.8.2",
 		"doctrine/common": "^3.5",
-		"roave/security-advisories": "dev-latest",
-		"phpunit/phpunit": "^12.2.5"
+		"phpunit/phpunit": "^12.2.5",
+		"roave/security-advisories": "dev-latest"
 	},
 	"autoload": {
 		"psr-4": {
@@ -35,6 +35,7 @@
 	},
 	"config": {
 		"allow-plugins": {
+			"21torr/janus": true,
 			"bamarni/composer-bin-plugin": true
 		},
 		"sort-packages": true
@@ -48,11 +49,11 @@
 	"scripts": {
 		"fix-lint": [
 			"@composer bin c-norm normalize \"$(pwd)/composer.json\" --indent-style tab --indent-size 1 --ansi",
-			"vendor-bin/cs-fixer/vendor/bin/php-cs-fixer fix --diff --config vendor-bin/cs-fixer/vendor/21torr/php-cs-fixer/.php-cs-fixer.dist.php --no-interaction --ansi"
+			"PHP_CS_FIXER_IGNORE_ENV=1 vendor-bin/cs-fixer/vendor/bin/php-cs-fixer fix --diff --config vendor-bin/cs-fixer/vendor/21torr/php-cs-fixer/.php-cs-fixer.dist.php --no-interaction --ansi"
 		],
 		"lint": [
 			"@composer bin c-norm normalize \"$(pwd)/composer.json\" --indent-style tab --indent-size 1 --dry-run --ansi",
-			"vendor-bin/cs-fixer/vendor/bin/php-cs-fixer check --diff --config vendor-bin/cs-fixer/vendor/21torr/php-cs-fixer/.php-cs-fixer.dist.php --no-interaction --ansi"
+			"PHP_CS_FIXER_IGNORE_ENV=1 vendor-bin/cs-fixer/vendor/bin/php-cs-fixer check --diff --config vendor-bin/cs-fixer/vendor/21torr/php-cs-fixer/.php-cs-fixer.dist.php --no-interaction --ansi"
 		],
 		"test": [
 			"phpunit",
diff --git a/phpstan.neon b/phpstan.neon
index 2300f7d..b567413 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -1,2 +1,14 @@
 includes:
 	- vendor/21torr/janus/phpstan/lib.neon
+
+parameters:
+
+# These are temporarily copied here, as normally they should be in the lib.neon of janus.
+# However, due to a bug in PHPStan, this currently doesn't work (https://github.com/phpstan/phpstan/issues/12844)
+	excludePaths:
+		analyse:
+			- vendor
+		analyseAndScan:
+			- node_modules (?)
+			- var (?)
+			- vendor-bin
diff --git a/src/Normalizer/SimpleNormalizer.php b/src/Normalizer/SimpleNormalizer.php
index 2e71627..61c1d70 100644
--- a/src/Normalizer/SimpleNormalizer.php
+++ b/src/Normalizer/SimpleNormalizer.php
@@ -18,6 +18,7 @@
  * = the object normalizers), as this way we can provide a full path to the invalid element in the JSON.
  *
  * @readonly
+ *
  * @final
  */
 class SimpleNormalizer
@@ -44,6 +45,7 @@ public function normalize (mixed $value, array $context = []) : mixed
 
 		return $normalizedValue;
 	}
+
 	/**
 	 */
 	public function normalizeArray (array $array, array $context = []) : array
@@ -75,8 +77,6 @@ public function normalizeMap (array $array, array $context = []) : array|\stdCla
 		return $normalizedValue;
 	}
 
-
-
 	/**
 	 * The actual normalize logic, that recursively normalizes the value.
 	 * It must never call one of the public methods above and just normalizes the value.
diff --git a/src/Normalizer/Validator/ValidJsonVerifier.php b/src/Normalizer/Validator/ValidJsonVerifier.php
index 1b4c346..9fcc0bd 100644
--- a/src/Normalizer/Validator/ValidJsonVerifier.php
+++ b/src/Normalizer/Validator/ValidJsonVerifier.php
@@ -21,7 +21,7 @@ public function ensureValidOnlyJsonTypes (mixed $value) : void
 		if (null !== $invalidElement)
 		{
 			throw new IncompleteNormalizationException(
-				sprintf(
+				\sprintf(
 					"Found a JSON-incompatible value when normalizing. Found '%s' at path '%s', but expected only scalars, arrays and empty objects.",
 					get_debug_type($invalidElement->value),
 					implode(".", $invalidElement->path),
@@ -30,12 +30,11 @@ public function ensureValidOnlyJsonTypes (mixed $value) : void
 		}
 	}
 
-
 	/**
 	 * Searches through the value and looks for anything that isn't valid JSON
 	 * (scalars, arrays or empty objects).
 	 *
-	 * @return InvalidJsonElement|null Returns null if everything is valid, otherwise the invalid value.
+	 * @return InvalidJsonElement|null returns null if everything is valid, otherwise the invalid value
 	 */
 	private function findInvalidJsonElement (mixed $value, array $path = ["$"]) : ?InvalidJsonElement
 	{
@@ -46,14 +45,14 @@ private function findInvalidJsonElement (mixed $value, array $path = ["$"]) : ?I
 		}
 
 		// only empty stdClass objects are allowed (as they are used to serialize to `{}`)
-		if (is_object($value))
+		if (\is_object($value))
 		{
 			return $value instanceof \stdClass && [] === get_object_vars($value)
 				? null
 				: new InvalidJsonElement($value, $path);
 		}
 
-		if (is_array($value))
+		if (\is_array($value))
 		{
 			foreach ($value as $key => $item)
 			{
diff --git a/tests/Normalizer/SimpleNormalizerTest.php b/tests/Normalizer/SimpleNormalizerTest.php
index 3ee28cf..d2043b3 100644
--- a/tests/Normalizer/SimpleNormalizerTest.php
+++ b/tests/Normalizer/SimpleNormalizerTest.php
@@ -3,15 +3,18 @@
 namespace Tests\Torr\SimpleNormalizer\Normalizer;
 
 use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\TestCase;
 use Symfony\Component\DependencyInjection\ServiceLocator;
 use Tests\Torr\SimpleNormalizer\Fixture\DummyVO;
 use Torr\SimpleNormalizer\Exception\IncompleteNormalizationException;
 use Torr\SimpleNormalizer\Normalizer\SimpleNormalizer;
-use PHPUnit\Framework\TestCase;
 use Torr\SimpleNormalizer\Normalizer\SimpleObjectNormalizerInterface;
 use Torr\SimpleNormalizer\Normalizer\Validator\ValidJsonVerifier;
 
-class SimpleNormalizerTest extends TestCase
+/**
+ * @internal
+ */
+final class SimpleNormalizerTest extends TestCase
 {
 	/**
 	 *
@@ -40,7 +43,7 @@ public function testJsonVerifierEnabled (callable $call) : void
 		$verifier = $this->createMock(ValidJsonVerifier::class);
 
 		$verifier
-			->expects($this->once())
+			->expects(self::once())
 			->method('ensureValidOnlyJsonTypes');
 
 		$normalizer = new SimpleNormalizer(
@@ -59,7 +62,6 @@ public function testJsonVerifierEnabled (callable $call) : void
 		]);
 	}
 
-
 	/**
 	 *
 	 */
@@ -68,7 +70,7 @@ public function testJsonVerifierDisabled () : void
 		$verifier = $this->createMock(ValidJsonVerifier::class);
 
 		$verifier
-			->expects($this->never())
+			->expects(self::never())
 			->method('ensureValidOnlyJsonTypes');
 
 		$normalizer = new SimpleNormalizer(
@@ -83,7 +85,6 @@ public function testJsonVerifierDisabled () : void
 		self::assertTrue(true); // Just to ensure the test runs without exceptions
 	}
 
-
 	/**
 	 *
 	 */
@@ -100,7 +101,6 @@ public function testInvalidNormalizer () : void
 		$normalizer->normalize(new DummyVO(42));
 	}
 
-
 	/**
 	 *
 	 */
@@ -124,15 +124,13 @@ public function testInvalidNestedNormalizer () : void
 		]);
 	}
 
-
 	/**
-	 *
+	 * @return ServiceLocator<mixed>
 	 */
 	private function createNormalizerObjectNormalizers (mixed $returnValue) : ServiceLocator
 	{
 		return new ServiceLocator([
-			DummyVO::class => static fn () => new readonly class ($returnValue) implements SimpleObjectNormalizerInterface
-			{
+			DummyVO::class => static fn () => new readonly class($returnValue) implements SimpleObjectNormalizerInterface {
 				public function __construct (
 					private mixed $returnValue,
 				) {}
diff --git a/vendor-bin/c-norm/composer.json b/vendor-bin/c-norm/composer.json
index 29d96fe..43031c1 100644
--- a/vendor-bin/c-norm/composer.json
+++ b/vendor-bin/c-norm/composer.json
@@ -1,6 +1,6 @@
 {
 	"require-dev": {
-		"ergebnis/composer-normalize": "^2.42",
+		"ergebnis/composer-normalize": "^2.47",
 		"roave/security-advisories": "dev-latest"
 	},
 	"config": {
diff --git a/vendor-bin/cs-fixer/composer.json b/vendor-bin/cs-fixer/composer.json
index ceadfce..42e20ab 100644
--- a/vendor-bin/cs-fixer/composer.json
+++ b/vendor-bin/cs-fixer/composer.json
@@ -1,6 +1,6 @@
 {
 	"require-dev": {
-		"21torr/php-cs-fixer": "^1.1.1",
+		"21torr/php-cs-fixer": "^1.1.5",
 		"roave/security-advisories": "dev-latest"
 	}
 }
diff --git a/vendor-bin/phpstan/composer.json b/vendor-bin/phpstan/composer.json
index cf165ff..4eb9387 100644
--- a/vendor-bin/phpstan/composer.json
+++ b/vendor-bin/phpstan/composer.json
@@ -3,14 +3,14 @@
 		"php": "^8.3"
 	},
 	"require-dev": {
-		"phpstan/extension-installer": "^1.3.1",
-		"phpstan/phpstan": "^1.11",
-		"phpstan/phpstan-deprecation-rules": "^1.2",
-		"phpstan/phpstan-doctrine": "^1.4",
-		"phpstan/phpstan-phpunit": "^1.4",
-		"phpstan/phpstan-symfony": "^1.4",
+		"phpstan/extension-installer": "^1.4.2",
+		"phpstan/phpstan": "^2.1.11",
+		"phpstan/phpstan-deprecation-rules": "^2.0.1",
+		"phpstan/phpstan-doctrine": "^2.0.2",
+		"phpstan/phpstan-phpunit": "^2.0.6",
+		"phpstan/phpstan-symfony": "^2.0.4",
 		"roave/security-advisories": "dev-latest",
-		"staabm/phpstan-todo-by": "^0.1.25"
+		"staabm/phpstan-todo-by": "^0.2"
 	},
 	"config": {
 		"sort-packages": true,