diff --git a/Dockerfile b/Dockerfile
index 81b1867..c971a04 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 # Read how to launch here: docs/docker.md
 
-FROM php:7.4-apache
+FROM php:8.1-apache
 
 MAINTAINER Joël Gaujard <j.gaujard@gmail.com>
 
diff --git a/composer.json b/composer.json
index b485e75..1615af8 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,7 @@
         }
     ],
     "require": {
-        "php": ">=7.2",
+        "php": ">=8.1",
         "ext-json": "*",
         "guzzlehttp/guzzle": "^7.0"
     },
diff --git a/src/Exception/UnexpectedValueException.php b/src/Exception/UnexpectedValueException.php
index 893e605..ad68e89 100644
--- a/src/Exception/UnexpectedValueException.php
+++ b/src/Exception/UnexpectedValueException.php
@@ -6,7 +6,7 @@
 
 class UnexpectedValueException extends \UnexpectedValueException
 {
-    public function __construct(string $message, int $code = null, Throwable $previous = null)
+    public function __construct(string $message, int $code = 0, Throwable $previous = null)
     {
         parent::__construct($message, $code, $previous);
     }