diff --git a/src/DependencyInjection/XiideaEasyImgProxyExtension.php b/src/DependencyInjection/XiideaEasyImgProxyExtension.php
index 75219ce..6fb05ee 100644
--- a/src/DependencyInjection/XiideaEasyImgProxyExtension.php
+++ b/src/DependencyInjection/XiideaEasyImgProxyExtension.php
@@ -30,9 +30,8 @@ public function load(array $configs, ContainerBuilder $container): void
         // Build and register presets
         $registry = $container->getDefinition(PresetRegistry::class);
         foreach ($config['presets'] ?? [] as $presetName => $presetConfig) {
-            $preset = new Preset(
-                $presetConfig['options'] ?? [],
-                $presetConfig['extension'] ?? null
+            $preset = new \Symfony\Component\DependencyInjection\Definition(
+                Preset::class, [$presetConfig['options'] ?? [], $presetConfig['extension'] ?? null]
             );
             $registry->addMethodCall('register', [$presetName, $preset]);
         }
diff --git a/tests/Unit/DependencyInjection/XiideaEasyImgProxyExtensionTest.php b/tests/Unit/DependencyInjection/XiideaEasyImgProxyExtensionTest.php
new file mode 100644
index 0000000..28a63d3
--- /dev/null
+++ b/tests/Unit/DependencyInjection/XiideaEasyImgProxyExtensionTest.php
@@ -0,0 +1,163 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Xiidea\EasyImgProxyBundle\Tests\Unit\DependencyInjection;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Xiidea\EasyImgProxyBundle\DependencyInjection\XiideaEasyImgProxyExtension;
+use Xiidea\EasyImgProxyBundle\Preset\PresetRegistry;
+use Xiidea\EasyImgProxyBundle\Service\ImgProxyUrlGenerator;
+
+class XiideaEasyImgProxyExtensionTest extends TestCase
+{
+    private XiideaEasyImgProxyExtension $extension;
+    private ContainerBuilder $container;
+
+    protected function setUp(): void
+    {
+        $this->extension = new XiideaEasyImgProxyExtension();
+        $this->container = new ContainerBuilder();
+    }
+
+    public function testLoadSetsRequiredParameters(): void
+    {
+        $configs = [[
+            'key' => 'test_key_123',
+            'salt' => 'test_salt_456',
+            'base_url' => 'https://imgproxy.example.com',
+        ]];
+
+        $this->extension->load($configs, $this->container);
+
+        $this->assertSame('test_key_123', $this->container->getParameter('xiidea_easy_img_proxy.key'));
+        $this->assertSame('test_salt_456', $this->container->getParameter('xiidea_easy_img_proxy.salt'));
+        $this->assertSame('https://imgproxy.example.com', $this->container->getParameter('xiidea_easy_img_proxy.base_url'));
+    }
+
+    public function testLoadSetsOptionalBooleanParameters(): void
+    {
+        $configs = [[
+            'key' => 'key',
+            'salt' => 'salt',
+            'base_url' => 'https://imgproxy.example.com',
+            'presets_only' => true,
+            'enable_pro' => true,
+        ]];
+
+        $this->extension->load($configs, $this->container);
+
+        $this->assertTrue($this->container->getParameter('xiidea_easy_img_proxy.presets_only'));
+        $this->assertTrue($this->container->getParameter('xiidea_easy_img_proxy.enable_pro'));
+    }
+
+    public function testLoadSetsDefaultBooleanParameters(): void
+    {
+        $configs = [[
+            'key' => 'key',
+            'salt' => 'salt',
+            'base_url' => 'https://imgproxy.example.com',
+        ]];
+
+        $this->extension->load($configs, $this->container);
+
+        $this->assertFalse($this->container->getParameter('xiidea_easy_img_proxy.presets_only'));
+        $this->assertFalse($this->container->getParameter('xiidea_easy_img_proxy.enable_pro'));
+    }
+
+    public function testLoadRegistersServicesViasPhpFileLoader(): void
+    {
+        $configs = [[
+            'key' => 'key',
+            'salt' => 'salt',
+            'base_url' => 'https://imgproxy.example.com',
+        ]];
+
+        // The services are loaded via PhpFileLoader during load()
+        // This test verifies the load method completes without error
+        // and parameters are set (which enables services to be properly configured)
+        $this->extension->load($configs, $this->container);
+
+        // Services will be registered through the PhpFileLoader
+        $this->assertTrue($this->container->has(PresetRegistry::class));
+        $this->assertTrue($this->container->has(ImgProxyUrlGenerator::class));
+    }
+
+    public function testLoadRegistersPresetsInRegistry(): void
+    {
+        $configs = [[
+            'key' => 'key',
+            'salt' => 'salt',
+            'base_url' => 'https://imgproxy.example.com',
+            'presets' => [
+                'thumbnail' => [
+                    'options' => ['width' => 100, 'height' => 100],
+                    'extension' => 'jpg',
+                ],
+                'medium' => [
+                    'options' => ['width' => 500, 'height' => 500],
+                ],
+            ],
+        ]];
+
+        $this->extension->load($configs, $this->container);
+
+        $registryDef = $this->container->getDefinition(PresetRegistry::class);
+        $calls = $registryDef->getMethodCalls();
+
+        // Verify presets were registered with the registry
+        $presetCalls = array_filter($calls, fn($call) => $call[0] === 'register');
+        $this->assertCount(2, $presetCalls);
+    }
+
+    public function testLoadWithEmptyPresets(): void
+    {
+        $configs = [[
+            'key' => 'key',
+            'salt' => 'salt',
+            'base_url' => 'https://imgproxy.example.com',
+            'presets' => [],
+        ]];
+
+        $this->extension->load($configs, $this->container);
+
+        $registryDef = $this->container->getDefinition(PresetRegistry::class);
+        $calls = $registryDef->getMethodCalls();
+        $presetCalls = array_filter($calls, fn($call) => $call[0] === 'register');
+
+        $this->assertCount(0, $presetCalls);
+    }
+
+    public function testLoadWithoutPresetsKey(): void
+    {
+        $configs = [[
+            'key' => 'key',
+            'salt' => 'salt',
+            'base_url' => 'https://imgproxy.example.com',
+        ]];
+
+        $this->extension->load($configs, $this->container);
+
+        // Should not throw an error, presets should be empty
+        $this->assertTrue($this->container->has(PresetRegistry::class));
+    }
+
+    public function testImgProxyUrlGeneratorDefinitionExists(): void
+    {
+        $configs = [[
+            'key' => 'test_key',
+            'salt' => 'test_salt',
+            'base_url' => 'https://imgproxy.example.com',
+            'presets_only' => true,
+            'enable_pro' => false,
+        ]];
+
+        $this->extension->load($configs, $this->container);
+
+        // Verify the service definition exists
+        $this->assertTrue($this->container->has(ImgProxyUrlGenerator::class));
+        $generatorDef = $this->container->getDefinition(ImgProxyUrlGenerator::class);
+        $this->assertNotNull($generatorDef);
+    }
+}
\ No newline at end of file