diff --git a/src/Eccube/Kernel.php b/src/Eccube/Kernel.php
index 8a3b36e1ced..8836f567f17 100644
--- a/src/Eccube/Kernel.php
+++ b/src/Eccube/Kernel.php
@@ -110,6 +110,16 @@ public function registerBundles(): iterable
                 }
             }
         }
+
+        $customizeBundles = $this->getProjectDir().'/app/Customize/Resource/config/bundles.php';
+        if (file_exists($customizeBundles)) {
+            $contents = require $customizeBundles;
+            foreach ($contents as $class => $envs) {
+                if (isset($envs['all']) || isset($envs[$this->environment])) {
+                    yield new $class();
+                }
+            }
+        }
     }
 
     /**
diff --git a/tests/Eccube/Tests/CustomizeBundleTest.php b/tests/Eccube/Tests/CustomizeBundleTest.php
new file mode 100644
index 00000000000..23bc253a3a2
--- /dev/null
+++ b/tests/Eccube/Tests/CustomizeBundleTest.php
@@ -0,0 +1,57 @@
+<?php
+
+/*
+ * This file is part of EC-CUBE
+ *
+ * Copyright(c) EC-CUBE CO.,LTD. All Rights Reserved.
+ *
+ * http://www.ec-cube.co.jp/
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Eccube\Tests;
+
+use Customize\Bundle\CustomizeBundle;
+use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
+use Symfony\Component\Filesystem\Filesystem;
+
+class CustomizeBundleTest extends KernelTestCase
+{
+    public function tearDown(): void
+    {
+        $fs = new Filesystem();
+        $fs->remove(__DIR__.'/../../../app/Customize/Bundle');
+        $fs->remove(__DIR__.'/../../../app/Customize/Resource/config/bundles.php');
+
+        parent::tearDown();
+    }
+
+    public function testContainsCustomizeBundle()
+    {
+        $fs = new Filesystem();
+        $originDir = __DIR__.'/../../Fixtures/Customize';
+        $targetDir = __DIR__.'/../../../app/Customize';
+        $fs->mirror($originDir, $targetDir);
+
+        $kernel = static::bootKernel();
+        $bundleNames = [];
+        foreach ($kernel->getBundles() as $bundle) {
+            $bundleNames[] = get_class($bundle);
+        }
+
+        self::assertContains(CustomizeBundle::class, $bundleNames);
+    }
+
+    public function testNotContainsCustomizeBundle()
+    {
+        $kernel = static::bootKernel();
+        $bundleNames = [];
+        foreach ($kernel->getBundles() as $bundle) {
+            $bundleNames[] = get_class($bundle);
+        }
+
+        self::assertNotContains(CustomizeBundle::class, $bundleNames);
+    }
+}
diff --git a/tests/Fixtures/Customize/Bundle/CustomizeBundle.php b/tests/Fixtures/Customize/Bundle/CustomizeBundle.php
new file mode 100644
index 00000000000..d05b4aaeb6c
--- /dev/null
+++ b/tests/Fixtures/Customize/Bundle/CustomizeBundle.php
@@ -0,0 +1,21 @@
+<?php
+
+/*
+ * This file is part of EC-CUBE
+ *
+ * Copyright(c) EC-CUBE CO.,LTD. All Rights Reserved.
+ *
+ * http://www.ec-cube.co.jp/
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Customize\Bundle;
+
+use Customize\DependencyInjection\CustomizeExtension;
+use Symfony\Component\HttpKernel\Bundle\Bundle;
+
+class CustomizeBundle extends Bundle
+{
+}
diff --git a/tests/Fixtures/Customize/Resource/config/bundles.php b/tests/Fixtures/Customize/Resource/config/bundles.php
new file mode 100644
index 00000000000..3834f313a15
--- /dev/null
+++ b/tests/Fixtures/Customize/Resource/config/bundles.php
@@ -0,0 +1,16 @@
+<?php
+
+/*
+ * This file is part of EC-CUBE
+ *
+ * Copyright(c) EC-CUBE CO.,LTD. All Rights Reserved.
+ *
+ * http://www.ec-cube.co.jp/
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+return [
+    Customize\Bundle\CustomizeBundle::class => ['all' => true],
+];