diff --git a/Config/config.php b/Config/config.php
index e67c03c..2bb6e56 100644
--- a/Config/config.php
+++ b/Config/config.php
@@ -29,7 +29,7 @@
             "router",
             "translator",
             "monolog.logger.mautic",
-            "mautic.helper.encryption",
+            "mautic.multicaptcha.helper.encryption",
             "mautic.lead.model.lead",
             "mautic.lead.model.company",
             "mautic.helper.paths",
@@ -50,7 +50,7 @@
             "router",
             "translator",
             "monolog.logger.mautic",
-            "mautic.helper.encryption",
+            "mautic.multicaptcha.helper.encryption",
             "mautic.lead.model.lead",
             "mautic.lead.model.company",
             "mautic.helper.paths",
diff --git a/Config/services.php b/Config/services.php
index 3d10d55..547b43a 100644
--- a/Config/services.php
+++ b/Config/services.php
@@ -3,6 +3,7 @@
 use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
 
 use Mautic\CoreBundle\DependencyInjection\MauticCoreExtension;
+use Mautic\CoreBundle\Helper\EncryptionHelper;
 
 return static function(ContainerConfigurator $configurator): void {
     $services = $configurator->services()
@@ -11,6 +12,9 @@
                              ->autoconfigure()
                              ->public();
 
+    // Legacy config.php treats FQCN arguments as strings, so use a local service alias.
+    $services->alias("mautic.multicaptcha.helper.encryption", EncryptionHelper::class);
+
     $services->load("MauticPlugin\\MauticMultiCaptchaBundle\\", "../")
              ->exclude(sprintf("../{%s}", implode(",", MauticCoreExtension::DEFAULT_EXCLUDES)));
 };
diff --git a/README.md b/README.md
index 074ae45..ca26433 100644
--- a/README.md
+++ b/README.md
@@ -76,3 +76,17 @@ Add the "Cloudflare Turnstile" field to the form and save changes.
 | Explicit consent mode:                                                                             | Implicit consent mode:                                                                                                                        |
 |----------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------|
 | ![Cloudflare Turnstile](.github/doc/turnstile_preview.png "Mautic Form with Cloudflare Turnstile") | ![Cloudflare Turnstile implied consent](.github/doc/turnstile_preview_implicit.png "Mautic Form with Cloudflare Turnstile (implied consent)") |
+
+## Integration service regression test
+
+With this plugin installed in a Mautic checkout, run the following as the Mautic
+filesystem user (use the project root containing `vendor/autoload.php`):
+
+```sh
+MAUTIC_ROOT=/path/to/mautic php -d memory_limit=1G plugins/MauticMultiCaptchaBundle/Tests/integration-services.php
+```
+
+For a Composer installation, the script is under `docroot/plugins/` instead.
+The test compiles a fresh container in a temporary cache directory, instantiates
+all three CAPTCHA integrations, and removes its cache afterward. It does not
+change integration settings or validate challenges with external providers.
diff --git a/Tests/integration-services.php b/Tests/integration-services.php
new file mode 100644
index 0000000..5d5eb37
--- /dev/null
+++ b/Tests/integration-services.php
@@ -0,0 +1,59 @@
+<?php declare(strict_types=1);
+
+// Run against an installed Mautic with this plugin in its plugins directory.
+// MAUTIC_ROOT=/path/to/mautic php -d memory_limit=1G Tests/integration-services.php
+$root = realpath(getenv('MAUTIC_ROOT') ?: '');
+if (!$root || !is_file($root . '/vendor/autoload.php')) {
+    fwrite(STDERR, "Set MAUTIC_ROOT to the Mautic project root containing vendor/autoload.php.\n");
+    exit(1);
+}
+
+$applicationDir = is_dir($root . '/docroot/app') ? $root . '/docroot' : $root;
+chdir($root);
+defined('IN_MAUTIC_CONSOLE') or define('IN_MAUTIC_CONSOLE', 1);
+defined('MAUTIC_ROOT_DIR') or define('MAUTIC_ROOT_DIR', $applicationDir);
+require $applicationDir . '/app/config/bootstrap.php';
+
+class MultiCaptchaTestKernel extends AppKernel
+{
+    public function __construct(private string $testRoot, private string $testCache)
+    {
+        parent::__construct('prod', false);
+    }
+
+    public function getProjectDir(): string
+    {
+        return $this->testRoot;
+    }
+
+    public function getCacheDir(): string
+    {
+        return $this->testCache;
+    }
+}
+
+$cache = sys_get_temp_dir() . '/multicaptcha-services-' . bin2hex(random_bytes(8));
+$kernel = new MultiCaptchaTestKernel($root, $cache);
+$status = 0;
+try {
+    // A fresh container is essential: an existing prod cache can hide broken wiring.
+    $kernel->boot();
+    $container = $kernel->getContainer();
+    foreach (['hcaptcha' => 'Hcaptcha', 'recaptcha' => 'Recaptcha', 'turnstile' => 'Turnstile'] as $id => $name) {
+        $expected = 'MauticPlugin\\MauticMultiCaptchaBundle\\Integration\\' . $name . 'Integration';
+        // Boot alone misses a literal class-name string injected instead of the helper.
+        $integration = $container->get('mautic.integration.' . $id);
+        if (!$integration instanceof $expected) {
+            throw new RuntimeException('Unexpected integration class for ' . $id);
+        }
+        echo 'PASS ' . $id . PHP_EOL;
+    }
+    echo 'PASS Mautic ' . $kernel->getVersion() . PHP_EOL;
+} catch (Throwable $exception) {
+    fwrite(STDERR, get_class($exception) . ': ' . $exception->getMessage() . PHP_EOL);
+    $status = 1;
+} finally {
+    $kernel->shutdown();
+    (new Symfony\Component\Filesystem\Filesystem())->remove($cache);
+}
+exit($status);