diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..cb445a2
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,3 @@
+/.github export-ignore
+/tests export-ignore
+/phpunit.xml.dist export-ignore
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
new file mode 100644
index 0000000..8e50e21
--- /dev/null
+++ b/.github/workflows/ci.yaml
@@ -0,0 +1,59 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  tests:
+    name: PHP ${{ matrix.php }}, ${{ matrix.name }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: lowest deps
+            php: '7.4'
+            flags: --prefer-lowest --prefer-stable
+          - name: Symfony 3.4
+            php: '7.4'
+            pins: symfony/config:3.4.* symfony/dependency-injection:3.4.* symfony/http-kernel:3.4.* symfony/yaml:3.4.*
+          - name: Symfony 4.4
+            php: '7.4'
+            pins: symfony/config:4.4.* symfony/dependency-injection:4.4.* symfony/http-kernel:4.4.* symfony/yaml:4.4.*
+          - name: Symfony 4.4
+            php: '8.1'
+            pins: symfony/config:4.4.* symfony/dependency-injection:4.4.* symfony/http-kernel:4.4.* symfony/yaml:4.4.*
+          - name: Symfony 5.4
+            php: '8.1'
+            pins: symfony/config:5.4.* symfony/dependency-injection:5.4.* symfony/http-kernel:5.4.* symfony/yaml:5.4.*
+          - name: Symfony 6.4
+            php: '8.2'
+            pins: symfony/config:6.4.* symfony/dependency-injection:6.4.* symfony/http-kernel:6.4.* symfony/yaml:6.4.*
+          - name: latest deps
+            php: '8.3'
+    env:
+      PINS: ${{ matrix.pins }}
+      COMPOSER_NO_SECURITY_BLOCKING: 1
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          tools: composer:v2
+          coverage: none
+
+      - name: Install dependencies
+        run: |
+          if [ -n "$PINS" ]; then composer require --no-update --no-interaction $PINS; fi
+          composer update --no-interaction --no-progress ${{ matrix.flags }}
+          composer show | grep -E '^(hubspot/hubspot-php|symfony/(config|dependency-injection|http-kernel|yaml)) '
+
+      - name: PHPUnit
+        run: vendor/bin/phpunit
diff --git a/composer.json b/composer.json
index 8e39caf..046ad63 100644
--- a/composer.json
+++ b/composer.json
@@ -19,9 +19,10 @@
     ],
     "require": {
         "php": "^7.4 || ^8.0",
-        "symfony/dependency-injection": "^2.8 || ^3.0 || ^4.0",
-        "symfony/config": "^2.8 || ^3.0 || ^4.0",
-        "symfony/http-kernel": "^2.8 || ^3.0 || ^4.0",
+        "symfony/dependency-injection": "^2.8 || ^3.0 || ^4.0 || ^5.4 || ^6.4",
+        "symfony/config": "^2.8 || ^3.0 || ^4.0 || ^5.4 || ^6.4",
+        "symfony/http-kernel": "^2.8 || ^3.0 || ^4.0 || ^5.4 || ^6.4",
+        "symfony/yaml": "^2.8 || ^3.0 || ^4.0 || ^5.4 || ^6.4",
         "hubspot/hubspot-php": "^3.1"
     },
     "require-dev": {
diff --git a/tests/DependencyInjection/HubSpotBundleTest.php b/tests/DependencyInjection/HubSpotBundleTest.php
new file mode 100644
index 0000000..8a155a1
--- /dev/null
+++ b/tests/DependencyInjection/HubSpotBundleTest.php
@@ -0,0 +1,48 @@
+<?php
+
+namespace DocPlanner\Bundle\HubSpotBundle\Tests\DependencyInjection;
+
+use DocPlanner\Bundle\HubSpotBundle\HubSpotBundle;
+use DocPlanner\Bundle\HubSpotBundle\Services\ProxyAwareFactory;
+use DocPlanner\Bundle\HubSpotBundle\Services\ProxyClient;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
+use Symfony\Component\DependencyInjection\Compiler\PassConfig;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Dumper\PhpDumper;
+
+final class HubSpotBundleTest extends TestCase
+{
+	public function testProxyConfiguredServiceBuilds(): void
+	{
+		$bundle    = new HubSpotBundle();
+		$container = new ContainerBuilder();
+		$container->registerExtension($bundle->getContainerExtension());
+		$container->loadFromExtension('hub_spot', [
+			'key'   => 'legacy-key',
+			'proxy' => [
+				'custom_url'     => 'https://proxy.example.com/hubspot-gateway',
+				'custom_headers' => ['x-api-key' => 'test-api-key', 'Authorization' => 'Bearer token'],
+			],
+		]);
+		$bundle->build($container);
+		$container->addCompilerPass(new PublicHubSpotPass(), PassConfig::TYPE_BEFORE_OPTIMIZATION);
+		$container->compile();
+
+		self::assertStringContainsString('class HubSpotTestContainer', (new PhpDumper($container))->dump(['class' => 'HubSpotTestContainer']));
+
+		$factory = $container->get('hubspot');
+		self::assertInstanceOf(ProxyAwareFactory::class, $factory);
+		$client = new \ReflectionProperty(ProxyAwareFactory::class, 'client');
+		$client->setAccessible(true);
+		self::assertInstanceOf(ProxyClient::class, $client->getValue($factory));
+	}
+}
+
+final class PublicHubSpotPass implements CompilerPassInterface
+{
+	public function process(ContainerBuilder $container)
+	{
+		$container->getDefinition('hubspot')->setPublic(true);
+	}
+}