diff --git a/config/services.php b/config/services.php
new file mode 100644
index 0000000..f0ab119
--- /dev/null
+++ b/config/services.php
@@ -0,0 +1,33 @@
+<?php
+// config/services.php
+
+use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
+use function Symfony\Component\DependencyInjection\Loader\Configurator\service;
+
+return static function (ContainerConfigurator $configurator): void {
+    $services = $configurator->services();
+
+    // sensible defaults
+    $services->defaults()
+        ->autowire()
+        ->autoconfigure()
+        ->private();
+
+    // The service that the compiler pass will inspect and modify.
+    // RequestMethodPass expects this service id and will replace argument index 1.
+    $services->set('beelab_recaptcha2.google_recaptcha', \Beelab\Recaptcha2Bundle\Recaptcha\RecaptchaVerifier::class)
+        ->args([
+            '%beelab_recaptcha2.secret%', // constructor arg 0 (the secret)
+            null,                         // constructor arg 1 (placeholder: replaced by RequestMethodPass)
+        ]);
+
+    // Validator service must match the string returned by Recaptcha2::validatedBy()
+    // Recaptcha2::validatedBy() returns 'recaptcha2' so we register the service id 'recaptcha2'.
+    $services->set('recaptcha2', \Beelab\Recaptcha2Bundle\Validator\Constraints\Recaptcha2Validator::class)
+        ->args([service('beelab_recaptcha2.google_recaptcha')])
+        ->tag('validator.constraint_validator');
+
+    // Form type
+    $services->set(\Beelab\Recaptcha2Bundle\Form\Type\RecaptchaType::class)
+        ->tag('form.type');
+};
diff --git a/src/DependencyInjection/BeelabRecaptcha2Extension.php b/src/DependencyInjection/BeelabRecaptcha2Extension.php
index 7f7d1ee..2115ba8 100644
--- a/src/DependencyInjection/BeelabRecaptcha2Extension.php
+++ b/src/DependencyInjection/BeelabRecaptcha2Extension.php
@@ -8,7 +8,7 @@
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Extension\Extension;
-use Symfony\Component\DependencyInjection\Loader;
+use Symfony\Component\DependencyInjection\Loader\PhpFileLoader;
 
 final class BeelabRecaptcha2Extension extends Extension
 {
@@ -23,8 +23,8 @@ public function load(array $configs, ContainerBuilder $container): void
         $requestMethodClass = $this->getRequestMethod($config['request_method']);
         $container->setParameter('beelab_recaptcha2.request_method', $requestMethodClass);
 
-        $loader = new Loader\XmlFileLoader($container, new FileLocator(__DIR__.'/../../config'));
-        $loader->load('services.xml');
+        $loader = new PhpFileLoader($container, new FileLocator(__DIR__.'/../../config'));
+        $loader->load('services.php');
     }
 
     private function getRequestMethod(string $requestMethod): string