diff --git a/src/BaseStub.php b/src/BaseStub.php
index d0a7eec..f83e0e5 100644
--- a/src/BaseStub.php
+++ b/src/BaseStub.php
@@ -30,7 +30,7 @@ protected function _simpleRequest(
         $method,
         $request,
         $deserialize,
-        array $metadata = []
+        array $metadata = [],
     ) {
         $streamId              = $this->client->send($method, $request);
         [$data, $trailers]     = $this->client->recv($streamId);
@@ -57,7 +57,7 @@ protected function _serverStreamRequest(
         $method,
         $request,
         $deserialize,
-        array $metadata = []
+        array $metadata = [],
     ) {
         $this->deserialize = $deserialize;
         $streamId          = $this->client->send($method, $request);
diff --git a/src/Exception/ClientException.php b/src/Exception/ClientException.php
index 7378098..c50e631 100644
--- a/src/Exception/ClientException.php
+++ b/src/Exception/ClientException.php
@@ -9,4 +9,6 @@
 
 namespace OpenSwoole\GRPC\Exception;
 
-class ClientException extends GRPCException {}
+class ClientException extends GRPCException
+{
+}
diff --git a/src/Exception/GRPCException.php b/src/Exception/GRPCException.php
index 746e764..e4b9f68 100644
--- a/src/Exception/GRPCException.php
+++ b/src/Exception/GRPCException.php
@@ -19,16 +19,16 @@ class GRPCException extends RuntimeException
 
     final public function __construct(
         string $message = '',
-        int $code = null,
-        Throwable $previous = null
+        ?int $code = null,
+        ?Throwable $previous = null,
     ) {
         parent::__construct($message, (int) ($code ?? static::CODE), $previous);
     }
 
     public static function create(
         string $message,
-        int $code = null,
-        Throwable $previous = null
+        ?int $code = null,
+        ?Throwable $previous = null,
     ): self {
         return new static($message, $code, $previous);
     }
diff --git a/src/MessageInterface.php b/src/MessageInterface.php
index d7cde01..652ffd2 100644
--- a/src/MessageInterface.php
+++ b/src/MessageInterface.php
@@ -9,4 +9,6 @@
 
 namespace OpenSwoole\GRPC;
 
-interface MessageInterface {}
+interface MessageInterface
+{
+}
diff --git a/src/Middleware/MiddlewareInterface.php b/src/Middleware/MiddlewareInterface.php
index ad44536..464a667 100644
--- a/src/Middleware/MiddlewareInterface.php
+++ b/src/Middleware/MiddlewareInterface.php
@@ -9,4 +9,6 @@
 
 namespace OpenSwoole\GRPC\Middleware;
 
-interface MiddlewareInterface {}
+interface MiddlewareInterface
+{
+}
diff --git a/src/RequestHandlerInterface.php b/src/RequestHandlerInterface.php
index 9277370..e375ddd 100644
--- a/src/RequestHandlerInterface.php
+++ b/src/RequestHandlerInterface.php
@@ -9,4 +9,6 @@
 
 namespace OpenSwoole\GRPC;
 
-interface RequestHandlerInterface {}
+interface RequestHandlerInterface
+{
+}
diff --git a/src/Server.php b/src/Server.php
index 5e8aadf..cb2bcc0 100644
--- a/src/Server.php
+++ b/src/Server.php
@@ -88,7 +88,7 @@ public function start()
         $this->server->set($this->settings);
         $this->server->on('workerStart', function (\OpenSwoole\Server $server, int $workerId) {
             $this->workerContext = new Context([
-                \OpenSwoole\GRPC\Server::class              => $this,
+                Server::class                               => $this,
                 \OpenSwoole\HTTP\Server::class              => $this->server,
             ]);
             foreach ($this->workerContexts as $context => $callback) {
@@ -107,7 +107,7 @@ public function on(string $event, Closure $callback)
         return $this;
     }
 
-    public function register(string $class, ServiceInterface $instance = null): self
+    public function register(string $class, ?ServiceInterface $instance = null): self
     {
         if (!class_exists($class)) {
             throw new TypeError("{$class} not found");
diff --git a/src/ServiceContainer.php b/src/ServiceContainer.php
index 122b239..1101693 100644
--- a/src/ServiceContainer.php
+++ b/src/ServiceContainer.php
@@ -120,7 +120,7 @@ private function discoverMethods(ServiceInterface $service): array
         $methods = [];
         foreach ($reflection->getMethods(ReflectionMethod::IS_PUBLIC) as $method) {
             // Check if its a gRPC method before doing this check
-            if (count($method->getParameters()) > 0 && $method->getParameteres()[0]->getName() == 'ctx') {
+            if (count($method->getParameters()) > 0 && $method->getParameters()[0]->getName() == 'ctx') {
                 // This is a gRPC method
                 if ($method->getNumberOfParameters() !== 2) {
                     throw new Exception('error method');
diff --git a/src/ServiceInterface.php b/src/ServiceInterface.php
index 9c16421..805a15c 100644
--- a/src/ServiceInterface.php
+++ b/src/ServiceInterface.php
@@ -9,4 +9,6 @@
 
 namespace OpenSwoole\GRPC;
 
-interface ServiceInterface {}
+interface ServiceInterface
+{
+}