diff --git a/src/Http/Exception.php b/src/Http/Exception.php
index 020347d..6199bc4 100644
--- a/src/Http/Exception.php
+++ b/src/Http/Exception.php
@@ -12,7 +12,7 @@ class Exception extends \Exception implements HttpExceptionInterface
     public function __construct(
         protected int $status,
         protected $message = '',
-        \Exception $previous = null,
+        ?\Exception $previous = null,
         protected array $headers = [],
         int $code = 0
     ) {
diff --git a/src/Http/Exception/HttpExceptionInterface.php b/src/Http/Exception/HttpExceptionInterface.php
index 460b727..e4c5d4f 100644
--- a/src/Http/Exception/HttpExceptionInterface.php
+++ b/src/Http/Exception/HttpExceptionInterface.php
@@ -8,7 +8,6 @@
 
 interface HttpExceptionInterface
 {
-
     public function buildJsonResponse(ResponseInterface $response): ResponseInterface;
     public function getHeaders(): array;
     public function getStatusCode(): int;
diff --git a/src/Middleware/MiddlewareAwareInterface.php b/src/Middleware/MiddlewareAwareInterface.php
index 37c1d35..afc4dd4 100644
--- a/src/Middleware/MiddlewareAwareInterface.php
+++ b/src/Middleware/MiddlewareAwareInterface.php
@@ -8,7 +8,6 @@
 
 interface MiddlewareAwareInterface
 {
-
     public function getMiddlewareStack(): iterable;
     public function lazyMiddleware(string $middleware): MiddlewareAwareInterface;
     public function lazyMiddlewares(array $middlewares): MiddlewareAwareInterface;