diff --git a/config/services.php b/config/services.php
index ee66e56f8c..fdff843efc 100644
--- a/config/services.php
+++ b/config/services.php
@@ -246,8 +246,7 @@
             ->arg(2, service('cache.easyadmin'))
             ->arg(3, service('filesystem'))
             ->arg(4, '%kernel.build_dir%')
-            ->arg(5, '%kernel.default_locale%')
-            ->arg(6, tagged_iterator(EasyAdminExtension::TAG_ADMIN_ROUTE_CONTROLLER))
+            ->arg(5, tagged_iterator(EasyAdminExtension::TAG_ADMIN_ROUTE_CONTROLLER))
 
         ->set(AdminRouteLoader::class)
             ->arg(0, service(AdminRouteGenerator::class))
diff --git a/src/Router/AdminRouteGenerator.php b/src/Router/AdminRouteGenerator.php
index 043e3e7d9d..36b6b89609 100644
--- a/src/Router/AdminRouteGenerator.php
+++ b/src/Router/AdminRouteGenerator.php
@@ -85,7 +85,6 @@ public function __construct(
         private readonly CacheItemPoolInterface $cache,
         private readonly Filesystem $filesystem,
         private readonly string $buildDir,
-        private readonly string $defaultLocale,
         private readonly iterable $adminRouteControllers = [],
     ) {
     }
@@ -210,7 +209,6 @@ private function generateAdminRoutes(): array
                     }
 
                     $defaults = [
-                        '_locale' => $this->defaultLocale,
                         '_controller' => $crudControllerFqcn.'::'.$actionRouteConfig['actionName'],
                         EA::ROUTE_CREATED_BY_EASYADMIN => true,
                         EA::DASHBOARD_CONTROLLER_FQCN => $dashboardFqcn,
diff --git a/tests/Functional/AdminRoute/AdminRouteTest.php b/tests/Functional/AdminRoute/AdminRouteTest.php
index ee94c7baa3..b1cfb9e6d7 100644
--- a/tests/Functional/AdminRoute/AdminRouteTest.php
+++ b/tests/Functional/AdminRoute/AdminRouteTest.php
@@ -605,6 +605,24 @@ public function testLegacyAttributesRoutesAreAccessible(): void
         $this->assertSame('Legacy export action', $client->getResponse()->getContent());
     }
 
+    public function testCrudRoutesDoNotSetLocaleDefault(): void
+    {
+        $client = static::createClient();
+        $router = $client->getContainer()->get('router');
+
+        // CRUD routes should NOT have '_locale' in defaults (regression test for #6842)
+        $crudRoute = $router->getRouteCollection()->get('admin_built_in_action_list');
+        $this->assertNotNull($crudRoute);
+        $this->assertArrayNotHasKey('_locale', $crudRoute->getDefaults(),
+            'CRUD routes must not set _locale in defaults, otherwise i18n prefix routing breaks');
+
+        // but routes with explicit '_locale' via #[AdminRoute] options should still have it
+        $invokableRoute = $router->getRouteCollection()->get('admin_custom_invokable');
+        $this->assertNotNull($invokableRoute);
+        $this->assertSame('en', $invokableRoute->getDefault('_locale'),
+            'Routes with explicit _locale in #[AdminRoute] options should keep it');
+    }
+
     public function testLegacyLinkToCrudMenuItemStillWorks(): void
     {
         $menuItem = MenuItem::linkToCrud('Products', 'fas fa-box', Product::class);
diff --git a/tests/Functional/AdminRoute/I18nAdminRouteTest.php b/tests/Functional/AdminRoute/I18nAdminRouteTest.php
new file mode 100644
index 0000000000..dd4f0f6c82
--- /dev/null
+++ b/tests/Functional/AdminRoute/I18nAdminRouteTest.php
@@ -0,0 +1,104 @@
+<?php
+
+namespace EasyCorp\Bundle\EasyAdminBundle\Tests\Functional\AdminRoute;
+
+use EasyCorp\Bundle\EasyAdminBundle\Tests\Functional\Apps\AdminRouteApp\I18nKernel;
+use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
+use Symfony\Component\Filesystem\Filesystem;
+
+/**
+ * @group legacy
+ */
+class I18nAdminRouteTest extends WebTestCase
+{
+    private const LOCALES = ['en', 'ja', 'es'];
+
+    protected static function getKernelClass(): string
+    {
+        return I18nKernel::class;
+    }
+
+    protected function setUp(): void
+    {
+        if (version_compare(\Symfony\Component\HttpKernel\Kernel::VERSION, '5.4.1', '<')) {
+            $this->markTestSkipped('AdminRoute attributes require Symfony 5.4.1 or higher');
+        }
+
+        parent::setUp();
+
+        $client = static::createClient();
+
+        $buildDir = $client->getKernel()->getContainer()->getParameter('kernel.build_dir');
+        $filesystem = new Filesystem();
+        $filesystem->touch($buildDir.'/easyadmin_pretty_urls_enabled');
+
+        self::ensureKernelShutdown();
+    }
+
+    protected function tearDown(): void
+    {
+        $filesystem = new Filesystem();
+        $cacheDir = sys_get_temp_dir().'/com.github.easycorp.easyadmin/tests/admin_route_i18n/var/test/cache';
+        $filesystem->remove($cacheDir.'/easyadmin_pretty_urls_enabled');
+
+        parent::tearDown();
+    }
+
+    public function testDashboardRoutesHaveLocaleVariants(): void
+    {
+        $client = static::createClient();
+        $router = $client->getContainer()->get('router');
+        $routes = $router->getRouteCollection();
+
+        foreach (['admin', 'second_admin'] as $dashboard) {
+            foreach (self::LOCALES as $locale) {
+                $routeName = $dashboard.'.'.$locale;
+                $route = $routes->get($routeName);
+
+                $this->assertNotNull($route, sprintf('Route "%s" should exist', $routeName));
+                $this->assertSame($locale, $route->getDefault('_locale'),
+                    sprintf('Route "%s" should have _locale default set to "%s"', $routeName, $locale));
+
+                $expectedPrefix = '/'.$locale.'/';
+                $this->assertStringStartsWith($expectedPrefix, $route->getPath(),
+                    sprintf('Route "%s" path should start with "%s"', $routeName, $expectedPrefix));
+            }
+        }
+    }
+
+    public function testCrudRoutesHaveLocaleVariants(): void
+    {
+        $client = static::createClient();
+        $router = $client->getContainer()->get('router');
+        $routes = $router->getRouteCollection();
+
+        $baseRouteName = 'admin_built_in_action_list';
+
+        foreach (self::LOCALES as $locale) {
+            $routeName = $baseRouteName.'.'.$locale;
+            $route = $routes->get($routeName);
+
+            $this->assertNotNull($route, sprintf('Route "%s" should exist', $routeName));
+            $this->assertSame($locale, $route->getDefault('_locale'),
+                sprintf('Route "%s" should have _locale default set to "%s"', $routeName, $locale));
+
+            $expectedPath = '/'.$locale.'/admin/built-in-action/index';
+            $this->assertSame($expectedPath, $route->getPath(),
+                sprintf('Route "%s" should have path "%s"', $routeName, $expectedPath));
+        }
+    }
+
+    public function testLocaleRoutesAreAccessible(): void
+    {
+        $client = static::createClient();
+
+        foreach (self::LOCALES as $locale) {
+            $client->request('GET', '/'.$locale.'/admin/foo/list');
+
+            $this->assertResponseIsSuccessful(
+                sprintf('Request to "/%s/admin/foo/list" should be successful', $locale)
+            );
+            $this->assertSame('Foo List', $client->getResponse()->getContent());
+        }
+    }
+}
diff --git a/tests/Functional/Apps/AdminRouteApp/config/i18n_routes.php b/tests/Functional/Apps/AdminRouteApp/config/i18n_routes.php
new file mode 100644
index 0000000000..7804b0b0d7
--- /dev/null
+++ b/tests/Functional/Apps/AdminRouteApp/config/i18n_routes.php
@@ -0,0 +1,8 @@
+<?php
+
+use Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator;
+
+return static function (RoutingConfigurator $routes) {
+    $routes->import('.', 'easyadmin.routes')
+        ->prefix(['en' => '/en', 'ja' => '/ja', 'es' => '/es']);
+};
diff --git a/tests/Functional/Apps/AdminRouteApp/src/I18nKernel.php b/tests/Functional/Apps/AdminRouteApp/src/I18nKernel.php
new file mode 100644
index 0000000000..d2129cb6b4
--- /dev/null
+++ b/tests/Functional/Apps/AdminRouteApp/src/I18nKernel.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace EasyCorp\Bundle\EasyAdminBundle\Tests\Functional\Apps\AdminRouteApp;
+
+use Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator;
+
+class I18nKernel extends Kernel
+{
+    public function getCacheDir(): string
+    {
+        return sys_get_temp_dir().'/com.github.easycorp.easyadmin/tests/admin_route_i18n/var/'.$this->environment.'/cache';
+    }
+
+    public function getLogDir(): string
+    {
+        return sys_get_temp_dir().'/com.github.easycorp.easyadmin/tests/admin_route_i18n/var/'.$this->environment.'/log';
+    }
+
+    protected function configureRoutes(RoutingConfigurator $routes): void
+    {
+        $routes->import($this->getProjectDir().'/config/i18n_routes.php');
+    }
+}
diff --git a/tests/Unit/Router/AdminRouteGeneratorTest.php b/tests/Unit/Router/AdminRouteGeneratorTest.php
index f7b73d5a0d..a63e0cfa27 100644
--- a/tests/Unit/Router/AdminRouteGeneratorTest.php
+++ b/tests/Unit/Router/AdminRouteGeneratorTest.php
@@ -64,7 +64,6 @@ public function testFindRoute(?string $dashboardControllerFqcn, ?string $crudCon
             $cacheMock,
             new Filesystem(),
             self::$kernel->getBuildDir(),
-            'en',
         );
 
         $routeName = $adminRouteGenerator->findRouteName($dashboardControllerFqcn, $crudControllerFqcn, $action);