diff --git a/InvalidRpcParamsException.php b/InvalidRpcParamsException.php
index 6e70463..df99ff2 100644
--- a/InvalidRpcParamsException.php
+++ b/InvalidRpcParamsException.php
@@ -4,6 +4,7 @@ namespace Kiri\Rpc;
 
 
 
+use JetBrains\PhpStorm\Pure;
 use Throwable;
 
 class InvalidRpcParamsException extends \Exception
@@ -15,7 +16,7 @@ class InvalidRpcParamsException extends \Exception
 	 * @param int $code
 	 * @param Throwable|null $previous
 	 */
-	public function __construct($message = "", $code = 0, Throwable $previous = null)
+	#[Pure] public function __construct(string $message = "", int $code = 0, Throwable $previous = null)
 	{
 		parent::__construct($message, -32602, $previous);
 	}