diff --git a/app/composer.lock b/app/composer.lock
index 161aad3..f521f49 100644
--- a/app/composer.lock
+++ b/app/composer.lock
@@ -127,16 +127,16 @@
         },
         {
             "name": "cakephp/core",
-            "version": "5.2.1",
+            "version": "5.2.3",
             "source": {
                 "type": "git",
                 "url": "https://github.com/cakephp/core.git",
-                "reference": "ba182a1410f1b06e8d1ab4d874b6f9797fbee165"
+                "reference": "a0a92ee7fbb7b7555dbf4ea7ff3fd4e779693da6"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/cakephp/core/zipball/ba182a1410f1b06e8d1ab4d874b6f9797fbee165",
-                "reference": "ba182a1410f1b06e8d1ab4d874b6f9797fbee165",
+                "url": "https://api.github.com/repos/cakephp/core/zipball/a0a92ee7fbb7b7555dbf4ea7ff3fd4e779693da6",
+                "reference": "a0a92ee7fbb7b7555dbf4ea7ff3fd4e779693da6",
                 "shasum": ""
             },
             "require": {
@@ -190,20 +190,20 @@
                 "issues": "https://github.com/cakephp/cakephp/issues",
                 "source": "https://github.com/cakephp/core"
             },
-            "time": "2025-04-02T12:02:03+00:00"
+            "time": "2025-04-19T12:34:03+00:00"
         },
         {
             "name": "cakephp/database",
-            "version": "5.2.1",
+            "version": "5.2.3",
             "source": {
                 "type": "git",
                 "url": "https://github.com/cakephp/database.git",
-                "reference": "f356a3fc78ff1c746d78786806f67ef22505cd76"
+                "reference": "8aa2df292e8b0e0c27e50bd6ed808fbf32f9c25a"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/cakephp/database/zipball/f356a3fc78ff1c746d78786806f67ef22505cd76",
-                "reference": "f356a3fc78ff1c746d78786806f67ef22505cd76",
+                "url": "https://api.github.com/repos/cakephp/database/zipball/8aa2df292e8b0e0c27e50bd6ed808fbf32f9c25a",
+                "reference": "8aa2df292e8b0e0c27e50bd6ed808fbf32f9c25a",
                 "shasum": ""
             },
             "require": {
@@ -257,20 +257,20 @@
                 "issues": "https://github.com/cakephp/cakephp/issues",
                 "source": "https://github.com/cakephp/database"
             },
-            "time": "2025-04-05T04:18:59+00:00"
+            "time": "2025-04-22T19:16:58+00:00"
         },
         {
             "name": "cakephp/datasource",
-            "version": "5.2.1",
+            "version": "5.2.3",
             "source": {
                 "type": "git",
                 "url": "https://github.com/cakephp/datasource.git",
-                "reference": "2b4f33fcc8c5d13261b851e8299c9fa85ff11b6e"
+                "reference": "a1e9d639d1e6ae28b32c57966373250c8b9f6d8b"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/cakephp/datasource/zipball/2b4f33fcc8c5d13261b851e8299c9fa85ff11b6e",
-                "reference": "2b4f33fcc8c5d13261b851e8299c9fa85ff11b6e",
+                "url": "https://api.github.com/repos/cakephp/datasource/zipball/a1e9d639d1e6ae28b32c57966373250c8b9f6d8b",
+                "reference": "a1e9d639d1e6ae28b32c57966373250c8b9f6d8b",
                 "shasum": ""
             },
             "require": {
@@ -324,20 +324,20 @@
                 "issues": "https://github.com/cakephp/cakephp/issues",
                 "source": "https://github.com/cakephp/datasource"
             },
-            "time": "2025-04-05T02:12:27+00:00"
+            "time": "2025-04-18T03:47:06+00:00"
         },
         {
             "name": "cakephp/utility",
-            "version": "5.2.1",
+            "version": "5.2.3",
             "source": {
                 "type": "git",
                 "url": "https://github.com/cakephp/utility.git",
-                "reference": "8b97361c71d30a9f1df2c8e98469d20af78d6ed6"
+                "reference": "76dcd5c20e46aaf5bfdf9ad51e9f5313abffe104"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/cakephp/utility/zipball/8b97361c71d30a9f1df2c8e98469d20af78d6ed6",
-                "reference": "8b97361c71d30a9f1df2c8e98469d20af78d6ed6",
+                "url": "https://api.github.com/repos/cakephp/utility/zipball/76dcd5c20e46aaf5bfdf9ad51e9f5313abffe104",
+                "reference": "76dcd5c20e46aaf5bfdf9ad51e9f5313abffe104",
                 "shasum": ""
             },
             "require": {
@@ -388,7 +388,7 @@
                 "issues": "https://github.com/cakephp/cakephp/issues",
                 "source": "https://github.com/cakephp/utility"
             },
-            "time": "2025-04-05T02:12:27+00:00"
+            "time": "2025-04-19T12:34:03+00:00"
         },
         {
             "name": "dflydev/dot-access-data",
@@ -1504,16 +1504,16 @@
         },
         {
             "name": "php-di/php-di",
-            "version": "7.0.9",
+            "version": "7.0.10",
             "source": {
                 "type": "git",
                 "url": "https://github.com/PHP-DI/PHP-DI.git",
-                "reference": "d8480267f5cf239650debba704f3ecd15b638cde"
+                "reference": "0d1ed64126577e9a095b3204dcaee58cf76432c2"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/PHP-DI/PHP-DI/zipball/d8480267f5cf239650debba704f3ecd15b638cde",
-                "reference": "d8480267f5cf239650debba704f3ecd15b638cde",
+                "url": "https://api.github.com/repos/PHP-DI/PHP-DI/zipball/0d1ed64126577e9a095b3204dcaee58cf76432c2",
+                "reference": "0d1ed64126577e9a095b3204dcaee58cf76432c2",
                 "shasum": ""
             },
             "require": {
@@ -1529,7 +1529,7 @@
                 "friendsofphp/php-cs-fixer": "^3",
                 "friendsofphp/proxy-manager-lts": "^1",
                 "mnapoli/phpunit-easymock": "^1.3",
-                "phpunit/phpunit": "^9.6",
+                "phpunit/phpunit": "^9.6 || ^10 || ^11",
                 "vimeo/psalm": "^5|^6"
             },
             "suggest": {
@@ -1561,7 +1561,7 @@
             ],
             "support": {
                 "issues": "https://github.com/PHP-DI/PHP-DI/issues",
-                "source": "https://github.com/PHP-DI/PHP-DI/tree/7.0.9"
+                "source": "https://github.com/PHP-DI/PHP-DI/tree/7.0.10"
             },
             "funding": [
                 {
@@ -1573,7 +1573,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2025-02-28T12:46:35+00:00"
+            "time": "2025-04-22T08:53:15+00:00"
         },
         {
             "name": "phpoption/phpoption",
@@ -2829,16 +2829,16 @@
         },
         {
             "name": "robmorgan/phinx",
-            "version": "0.16.6",
+            "version": "0.16.7",
             "source": {
                 "type": "git",
                 "url": "https://github.com/cakephp/phinx.git",
-                "reference": "5bad10934336e8cf45d50d529cabfcbe7fe287c5"
+                "reference": "edd61785fe6b57a5992afafcc8cfdf5ea612d50d"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/cakephp/phinx/zipball/5bad10934336e8cf45d50d529cabfcbe7fe287c5",
-                "reference": "5bad10934336e8cf45d50d529cabfcbe7fe287c5",
+                "url": "https://api.github.com/repos/cakephp/phinx/zipball/edd61785fe6b57a5992afafcc8cfdf5ea612d50d",
+                "reference": "edd61785fe6b57a5992afafcc8cfdf5ea612d50d",
                 "shasum": ""
             },
             "require": {
@@ -2850,8 +2850,8 @@
                 "symfony/console": "^6.0|^7.0"
             },
             "require-dev": {
-                "cakephp/cakephp": "^5.0.2",
                 "cakephp/cakephp-codesniffer": "^5.0",
+                "cakephp/i18n": "^5.0",
                 "ext-json": "*",
                 "ext-pdo": "*",
                 "phpunit/phpunit": "^9.5.19",
@@ -2910,9 +2910,9 @@
             ],
             "support": {
                 "issues": "https://github.com/cakephp/phinx/issues",
-                "source": "https://github.com/cakephp/phinx/tree/0.16.6"
+                "source": "https://github.com/cakephp/phinx/tree/0.16.7"
             },
-            "time": "2024-12-20T23:02:54+00:00"
+            "time": "2025-04-17T17:32:39+00:00"
         },
         {
             "name": "slim/flash",
@@ -5365,16 +5365,16 @@
         },
         {
             "name": "phpunit/phpunit",
-            "version": "11.5.17",
+            "version": "11.5.18",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/phpunit.git",
-                "reference": "fd2e863a2995cdfd864fb514b5e0b28b09895b5c"
+                "reference": "fc3e887c7f3f9917e1bf61e523413d753db00a17"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/fd2e863a2995cdfd864fb514b5e0b28b09895b5c",
-                "reference": "fd2e863a2995cdfd864fb514b5e0b28b09895b5c",
+                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/fc3e887c7f3f9917e1bf61e523413d753db00a17",
+                "reference": "fc3e887c7f3f9917e1bf61e523413d753db00a17",
                 "shasum": ""
             },
             "require": {
@@ -5446,7 +5446,7 @@
             "support": {
                 "issues": "https://github.com/sebastianbergmann/phpunit/issues",
                 "security": "https://github.com/sebastianbergmann/phpunit/security/policy",
-                "source": "https://github.com/sebastianbergmann/phpunit/tree/11.5.17"
+                "source": "https://github.com/sebastianbergmann/phpunit/tree/11.5.18"
             },
             "funding": [
                 {
@@ -5457,12 +5457,20 @@
                     "url": "https://github.com/sebastianbergmann",
                     "type": "github"
                 },
+                {
+                    "url": "https://liberapay.com/sebastianbergmann",
+                    "type": "liberapay"
+                },
+                {
+                    "url": "https://thanks.dev/u/gh/sebastianbergmann",
+                    "type": "thanks_dev"
+                },
                 {
                     "url": "https://tidelift.com/funding/github/packagist/phpunit/phpunit",
                     "type": "tidelift"
                 }
             ],
-            "time": "2025-04-08T07:59:11+00:00"
+            "time": "2025-04-22T06:09:49+00:00"
         },
         {
             "name": "sebastian/cli-parser",
diff --git a/app/src/Bootstrap.php b/app/src/Bootstrap.php
index ddff202..1a94e92 100644
--- a/app/src/Bootstrap.php
+++ b/app/src/Bootstrap.php
@@ -29,7 +29,6 @@ use Psr\Log\LoggerInterface;
 use Slim\App;
 use Slim\Factory\AppFactory;
 use Slim\Psr7\Factory\ResponseFactory;
-use Slovocast\Configuration\FileSystemSchema;
 use Slovocast\Middleware\SessionMiddleware;
 use Twig\Error\LoaderError;
 
diff --git a/app/src/Handler/AsyncHandler.php b/app/src/Handler/AsyncHandler.php
index 999c022..eaa82f1 100644
--- a/app/src/Handler/AsyncHandler.php
+++ b/app/src/Handler/AsyncHandler.php
@@ -12,16 +12,12 @@ abstract class AsyncHandler extends Handler
      */
     public function prepareResponse(array $data, string $template = ""): ResponseInterface 
     {
-        $acceptsHeader = $this->request->getHeader('Accept');
+        $acceptsHeaders = $this->request->getHeader('Accept');
 
-        switch ($acceptsHeader) {
-        case 'text/html':
+        if (in_array('text/html', $acceptsHeaders)) {
             return $this->renderInline($template, $data);
-            break;
-        case 'application/json':
-        default:
-            return $this->json($data);
-            break;
         }
+
+        return $this->json($data);
     }
 }
diff --git a/app/tests/Handler/AsyncHandlerTest.php b/app/tests/Handler/AsyncHandlerTest.php
new file mode 100644
index 0000000..6f396ca
--- /dev/null
+++ b/app/tests/Handler/AsyncHandlerTest.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Slovocast\Tests\Controller;
+
+use Slovocast\Tests\TestCase;
+use Slovocast\Handler\AsyncHandler;
+use Psr\Http\Message\ResponseInterface as Response;
+
+class AsyncHandlerTest extends TestCase
+{
+    public function testHtmlAcceptHeader(): void
+    {
+        $asyncHtmlHandler = new class extends AsyncHandler {
+            public function handle(): Response
+            {
+                $template = "<ul>
+                    {% for item in list %}
+                        <li>{{ item }}</li>
+                    {% endfor %}
+                </ul>";
+                
+                return $this->prepareResponse([ 'list' => [ 1, 2, 3 ]], $template);
+            }
+        };
+
+        $app = $this->getAppInstance();
+        $app->get('/test', $asyncHtmlHandler);
+
+        $request = $this->createRequest('GET', '/test', [ 'Accept' => 'text/html' ]);
+        $response = $app->handle($request);
+
+        $this->assertStringContainsString('<li>1</li>', $response->getBody());
+    }
+}
diff --git a/app/tests/Handler/HandlerTest.php b/app/tests/Handler/HandlerTest.php
index 03a2a55..743d3f1 100644
--- a/app/tests/Handler/HandlerTest.php
+++ b/app/tests/Handler/HandlerTest.php
@@ -7,7 +7,7 @@ use Slovocast\Handler\Handler;
 use Psr\Http\Message\ResponseInterface as Response;
 use Odan\Session\SessionInterface;
 
-class HandlerTest extends TestCase
+final class HandlerTest extends TestCase
 {
     public function testHtmlInlineResponse(): void
     {