diff --git a/composer.json b/composer.json
index ecf2148e25e..a55d94f2eb9 100644
--- a/composer.json
+++ b/composer.json
@@ -165,7 +165,7 @@
         "toflar/psr6-symfony-http-cache-store": "^4.0",
         "twig/extra-bundle": "^3.0",
         "twig/string-extra": "^3.0",
-        "twig/twig": "^3.8",
+        "twig/twig": "^3.10.2",
         "ua-parser/uap-php": "^3.9",
         "webignition/robots-txt-file": "^3.0",
         "wikimedia/less.php": "^1.7"
@@ -202,8 +202,6 @@
         "nikic/php-parser": "4.7.0",
         "terminal42/contao-ce-access": "<3.0",
         "thecodingmachine/safe": "<1.2",
-        "twig/intl-extra": "3.9.0",
-        "twig/twig": "3.9.0 || 3.10.0 || 3.10.1",
         "zendframework/zend-code": "<3.3.1"
     },
     "autoload": {
diff --git a/core-bundle/composer.json b/core-bundle/composer.json
index f6cc3500d96..33e7d47dcaf 100644
--- a/core-bundle/composer.json
+++ b/core-bundle/composer.json
@@ -151,7 +151,7 @@
         "terminal42/service-annotation-bundle": "^1.1",
         "toflar/cronjob-supervisor": "^2.0",
         "twig/string-extra": "^3.0",
-        "twig/twig": "^3.8",
+        "twig/twig": "^3.10.2",
         "ua-parser/uap-php": "^3.9",
         "webignition/robots-txt-file": "^3.0",
         "wikimedia/less.php": "^1.7"
@@ -179,9 +179,7 @@
         "contao/manager-plugin": "<2.0 || >=3.0",
         "doctrine/cache": "<1.10",
         "terminal42/contao-ce-access": "<3.0",
-        "thecodingmachine/safe": "<1.2",
-        "twig/intl-extra": "3.9.0",
-        "twig/twig": "3.9.0 || 3.10.0 || 3.10.1"
+        "thecodingmachine/safe": "<1.2"
     },
     "autoload": {
         "psr-4": {
diff --git a/core-bundle/config/routes.yaml b/core-bundle/config/routes.yaml
index c7efbf4262e..bdea61137b2 100644
--- a/core-bundle/config/routes.yaml
+++ b/core-bundle/config/routes.yaml
@@ -11,21 +11,7 @@ contao_backend_redirect:
     path: '%contao.backend.route_prefix%/'
     defaults:
         _scope: backend
+        _store_referrer: false
         _controller: Symfony\Bundle\FrameworkBundle\Controller\RedirectController::redirectAction
         route: contao_backend
         permanent: true
-
-contao_backend_fallback:
-    path: '%contao.backend.route_prefix%/{parameters}'
-    defaults:
-        _scope: backend
-        _controller: Symfony\Bundle\FrameworkBundle\Controller\TemplateController
-        template: '@ContaoCore\Error\backend.html.twig'
-        context:
-            template: '@ContaoCore\Error\backend.html.twig'
-            language: en
-            statusName: Page Not Found
-            exception: The requested page does not exist.
-        statusCode: 404
-    requirements:
-        parameters: .*
diff --git a/core-bundle/config/services.yaml b/core-bundle/config/services.yaml
index abcad4319dc..1680229c739 100644
--- a/core-bundle/config/services.yaml
+++ b/core-bundle/config/services.yaml
@@ -579,8 +579,6 @@ services:
         class: Contao\CoreBundle\Monolog\ContaoTableHandler
         arguments:
             - !service_closure '@database_connection'
-            - debug
-            - false
         tags:
             - { name: monolog.logger, channel: contao }
 
diff --git a/core-bundle/contao/drivers/DC_Table.php b/core-bundle/contao/drivers/DC_Table.php
index 3015d48913a..3d9bc486be3 100644
--- a/core-bundle/contao/drivers/DC_Table.php
+++ b/core-bundle/contao/drivers/DC_Table.php
@@ -1139,7 +1139,7 @@ protected function copyChildren($table, $insertID, $id, $parentId)
 			$this->loadDataContainer($v);
 			$cctable[$v] = $GLOBALS['TL_DCA'][$v]['config']['ctable'] ?? null;
 
-			if (!($GLOBALS['TL_DCA'][$v]['config']['doNotCopyRecords'] ?? null) && \strlen($v))
+			if (!($GLOBALS['TL_DCA'][$v]['config']['doNotCopyRecords'] ?? null))
 			{
 				// Consider the dynamic parent table (see #4867)
 				if ($GLOBALS['TL_DCA'][$v]['config']['dynamicPtable'] ?? null)
diff --git a/core-bundle/src/Controller/BackendController.php b/core-bundle/src/Controller/BackendController.php
index c6281545c74..e0162659737 100644
--- a/core-bundle/src/Controller/BackendController.php
+++ b/core-bundle/src/Controller/BackendController.php
@@ -44,8 +44,8 @@ public function mainAction(): Response
         return $controller->run();
     }
 
-    #[Route('/login', name: 'contao_backend_login')]
-    #[Route('/login-link', name: 'contao_backend_login_link')]
+    #[Route('/login', name: 'contao_backend_login', defaults: ['_store_referer' => false])]
+    #[Route('/login-link', name: 'contao_backend_login_link', defaults: ['_store_referer' => false])]
     public function loginAction(Request $request): Response
     {
         $this->initializeContaoFramework();
@@ -72,13 +72,13 @@ public function loginAction(Request $request): Response
     /**
      * Symfony will un-authenticate the user automatically by calling this route.
      */
-    #[Route('/logout', name: 'contao_backend_logout')]
+    #[Route('/logout', name: 'contao_backend_logout', defaults: ['_store_referer' => false])]
     public function logoutAction(): RedirectResponse
     {
         return $this->redirectToRoute('contao_backend_login');
     }
 
-    #[Route('/password', name: 'contao_backend_password')]
+    #[Route('/password', name: 'contao_backend_password', defaults: ['_store_referer' => false])]
     public function passwordAction(): Response
     {
         $this->initializeContaoFramework();
@@ -88,7 +88,7 @@ public function passwordAction(): Response
         return $controller->run();
     }
 
-    #[Route('/confirm', name: 'contao_backend_confirm')]
+    #[Route('/confirm', name: 'contao_backend_confirm', defaults: ['_store_referer' => false])]
     public function confirmAction(): Response
     {
         $this->initializeContaoFramework();
@@ -98,7 +98,7 @@ public function confirmAction(): Response
         return $controller->run();
     }
 
-    #[Route('/help', name: 'contao_backend_help')]
+    #[Route('/help', name: 'contao_backend_help', defaults: ['_store_referer' => false])]
     public function helpAction(): Response
     {
         $this->initializeContaoFramework();
@@ -108,7 +108,7 @@ public function helpAction(): Response
         return $controller->run();
     }
 
-    #[Route('/popup', name: 'contao_backend_popup')]
+    #[Route('/popup', name: 'contao_backend_popup', defaults: ['_store_referer' => false])]
     public function popupAction(): Response
     {
         $this->initializeContaoFramework();
@@ -118,7 +118,7 @@ public function popupAction(): Response
         return $controller->run();
     }
 
-    #[Route('/alerts', name: 'contao_backend_alerts')]
+    #[Route('/alerts', name: 'contao_backend_alerts', defaults: ['_store_referer' => false])]
     public function alertsAction(): Response
     {
         $this->initializeContaoFramework();
@@ -133,7 +133,7 @@ public function alertsAction(): Response
      * It will determine the current provider URL based on the value, which is usually
      * read dynamically via JavaScript.
      */
-    #[Route('/picker', name: 'contao_backend_picker')]
+    #[Route('/picker', name: 'contao_backend_picker', defaults: ['_store_referer' => false])]
     public function pickerAction(Request $request): RedirectResponse
     {
         $extras = [];
@@ -156,6 +156,21 @@ public function pickerAction(Request $request): RedirectResponse
         return new RedirectResponse($picker->getCurrentUrl());
     }
 
+    #[Route('/{parameters}', name: 'contao_backend_fallback', requirements: ['parameters' => '.*'], defaults: ['_store_referer' => false], priority: -1000)]
+    public function backendFallback(): Response
+    {
+        return $this->render(
+            '@ContaoCore/Error/backend.html.twig',
+            [
+                'language' => 'en',
+                'statusName' => 'Page Not Found',
+                'exception' => 'The requested page does not exist.',
+                'template' => '@ContaoCore/Error/backend.html.twig',
+            ],
+            new Response('', 404),
+        );
+    }
+
     public static function getSubscribedServices(): array
     {
         $services = parent::getSubscribedServices();
diff --git a/core-bundle/src/Controller/BackendPreviewController.php b/core-bundle/src/Controller/BackendPreviewController.php
index 57297c0b586..8e68877b658 100644
--- a/core-bundle/src/Controller/BackendPreviewController.php
+++ b/core-bundle/src/Controller/BackendPreviewController.php
@@ -31,7 +31,7 @@
  * requested front end page while ensuring that the /preview.php entry point is
  * used. When requested, the front end user gets authenticated.
  */
-#[Route('%contao.backend.route_prefix%', defaults: ['_scope' => 'backend', '_allow_preview' => true])]
+#[Route('%contao.backend.route_prefix%/preview', name: 'contao_backend_preview', defaults: ['_scope' => 'backend', '_allow_preview' => true, '_store_referrer' => false])]
 class BackendPreviewController
 {
     public function __construct(
@@ -44,7 +44,6 @@ public function __construct(
     ) {
     }
 
-    #[Route('/preview', name: 'contao_backend_preview')]
     public function __invoke(Request $request): Response
     {
         // Skip the redirect if there is no preview script, otherwise we will end up in
diff --git a/core-bundle/src/Controller/BackendPreviewSwitchController.php b/core-bundle/src/Controller/BackendPreviewSwitchController.php
index 2ec0f4063bf..90a3bdcb332 100644
--- a/core-bundle/src/Controller/BackendPreviewSwitchController.php
+++ b/core-bundle/src/Controller/BackendPreviewSwitchController.php
@@ -37,7 +37,7 @@
  * - Provide the member usernames for the datalist
  * - Process the switch action (i.e. log in a specific front end user)
  */
-#[Route('%contao.backend.route_prefix%', defaults: ['_scope' => 'backend', '_allow_preview' => true])]
+#[Route('%contao.backend.route_prefix%/preview_switch', name: 'contao_backend_switch', defaults: ['_scope' => 'backend', '_allow_preview' => true, '_store_referrer' => false])]
 class BackendPreviewSwitchController
 {
     public function __construct(
@@ -54,7 +54,6 @@ public function __construct(
     ) {
     }
 
-    #[Route('/preview_switch', name: 'contao_backend_switch')]
     public function __invoke(Request $request): Response
     {
         $user = $this->security->getUser();
diff --git a/core-bundle/src/EventListener/CsrfTokenCookieSubscriber.php b/core-bundle/src/EventListener/CsrfTokenCookieSubscriber.php
index 43b9b9a0170..e955a5d1dc0 100644
--- a/core-bundle/src/EventListener/CsrfTokenCookieSubscriber.php
+++ b/core-bundle/src/EventListener/CsrfTokenCookieSubscriber.php
@@ -120,6 +120,15 @@ private function requiresCsrf(Request $request, Response $response): bool
 
     private function isSessionEmpty(SessionInterface $session): bool
     {
+        foreach (headers_list() as $header) {
+            if (
+                str_starts_with($header, "Set-Cookie: {$session->getName()}=")
+                && !str_starts_with($header, "Set-Cookie: {$session->getName()}=deleted;")
+            ) {
+                return false;
+            }
+        }
+
         if (!$session->isStarted()) {
             return true;
         }
diff --git a/core-bundle/src/EventListener/MakeResponsePrivateListener.php b/core-bundle/src/EventListener/MakeResponsePrivateListener.php
index bceabb622f8..69d2eee5590 100644
--- a/core-bundle/src/EventListener/MakeResponsePrivateListener.php
+++ b/core-bundle/src/EventListener/MakeResponsePrivateListener.php
@@ -115,6 +115,15 @@ private function makePrivate(Response $response, string $reason): void
 
     private function isSessionEmpty(SessionInterface $session): bool
     {
+        foreach (headers_list() as $header) {
+            if (
+                str_starts_with($header, "Set-Cookie: {$session->getName()}=")
+                && !str_starts_with($header, "Set-Cookie: {$session->getName()}=deleted;")
+            ) {
+                return false;
+            }
+        }
+
         if (!$session->isStarted()) {
             return true;
         }
diff --git a/core-bundle/src/EventListener/StoreRefererListener.php b/core-bundle/src/EventListener/StoreRefererListener.php
index 6997031be61..d0f6668fcb2 100644
--- a/core-bundle/src/EventListener/StoreRefererListener.php
+++ b/core-bundle/src/EventListener/StoreRefererListener.php
@@ -91,7 +91,8 @@ private function canModifyBackendSession(Request $request): bool
             && !$request->query->has('token')
             && !$request->query->has('state')
             && 'feRedirect' !== $request->query->get('do')
-            && 'contao_backend' === $request->attributes->get('_route')
+            && 'backend' === $request->attributes->get('_scope')
+            && false !== $request->attributes->get('_store_referrer')
             && !$request->isXmlHttpRequest();
     }
 
diff --git a/core-bundle/src/Security/Voter/BackendAccessVoter.php b/core-bundle/src/Security/Voter/BackendAccessVoter.php
index ec9189fb14f..1ec2a6edb56 100644
--- a/core-bundle/src/Security/Voter/BackendAccessVoter.php
+++ b/core-bundle/src/Security/Voter/BackendAccessVoter.php
@@ -121,7 +121,7 @@ private function hasAccess(mixed $subject, string $field, BackendUser $user): bo
 
         // Additionally check the child pages of the mounted pages
         if ('pagemounts' === $field) {
-            if (!isset($this->pagemountsCache[$user->id])) {
+            if (!isset($this->pagemountsCache[$user->id]) || (!empty($this->pagemountsCache[$user->id]) && !array_intersect($subject, $this->pagemountsCache[$user->id]))) {
                 $database = $this->framework->createInstance(Database::class);
                 $this->pagemountsCache[$user->id] = $database->getChildRecords($user->pagemounts, 'tl_page');
             }
diff --git a/core-bundle/src/Twig/Extension/ContaoExtension.php b/core-bundle/src/Twig/Extension/ContaoExtension.php
index 3d1ce37129a..b07b2be4e31 100644
--- a/core-bundle/src/Twig/Extension/ContaoExtension.php
+++ b/core-bundle/src/Twig/Extension/ContaoExtension.php
@@ -48,10 +48,10 @@
 use Twig\Environment;
 use Twig\Extension\AbstractExtension;
 use Twig\Extension\CoreExtension;
-use Twig\Extension\EscaperExtension;
 use Twig\Extension\GlobalsInterface;
 use Twig\Node\Expression\ConstantExpression;
 use Twig\Node\Node;
+use Twig\Runtime\EscaperRuntime;
 use Twig\TwigFilter;
 use Twig\TwigFunction;
 
@@ -69,15 +69,10 @@ public function __construct(
         private readonly ContaoVariable $contaoVariable,
     ) {
         $contaoEscaper = new ContaoEscaper();
-        $escaperExtension = $environment->getExtension(EscaperExtension::class);
 
-        // Forward compatibility with twig/twig >=3.10.0
-        if (method_exists($escaperExtension, 'setEnvironment')) {
-            $escaperExtension->setEnvironment($environment);
-        }
-
-        $escaperExtension->setEscaper('contao_html', $contaoEscaper->escapeHtml(...));
-        $escaperExtension->setEscaper('contao_html_attr', $contaoEscaper->escapeHtmlAttr(...));
+        $escaperRuntime = $this->environment->getRuntime(EscaperRuntime::class);
+        $escaperRuntime->setEscaper('contao_html', $contaoEscaper->escapeHtml(...));
+        $escaperRuntime->setEscaper('contao_html_attr', $contaoEscaper->escapeHtmlAttr(...));
 
         // Use our escaper on all templates in the "@Contao" and "@Contao_*" namespaces,
         // as well as the existing bundle templates we're already shipping.
@@ -85,8 +80,8 @@ public function __construct(
         $this->addContaoEscaperRule('%^@ContaoCore/%');
 
         // Mark classes as safe for HTML that already escape their output themselves
-        $escaperExtension->addSafeClass(HtmlAttributes::class, ['html', 'contao_html']);
-        $escaperExtension->addSafeClass(HighlightResult::class, ['html', 'contao_html']);
+        $escaperRuntime->addSafeClass(HtmlAttributes::class, ['html', 'contao_html']);
+        $escaperRuntime->addSafeClass(HighlightResult::class, ['html', 'contao_html']);
 
         $this->environment->addGlobal(
             'request_token',
@@ -242,7 +237,9 @@ function (Environment $env, $context, $template, $variables = [], $withContext =
 
     public function getFilters(): array
     {
-        $escaperFilter = static function (Environment $env, $string, $strategy = 'html', $charset = null, $autoescape = false) {
+        $escaperFilter = static function (Environment $env, $string, string $strategy = 'html', string|null $charset = null, bool $autoescape = false) {
+            $runtime = $env->getRuntime(EscaperRuntime::class);
+
             if ($string instanceof ChunkedText) {
                 $parts = [];
 
@@ -250,31 +247,36 @@ public function getFilters(): array
                     if (ChunkedText::TYPE_RAW === $type) {
                         $parts[] = $chunk;
                     } else {
-                        $parts[] = twig_escape_filter($env, $chunk, $strategy, $charset);
+                        $parts[] = $runtime->escape($chunk, $strategy, $charset);
                     }
                 }
 
                 return implode('', $parts);
             }
 
-            return twig_escape_filter($env, $string, $strategy, $charset, $autoescape);
+            return $runtime->escape($string, $strategy, $charset, $autoescape);
         };
 
+        /** @see \Twig\Extension\EscaperExtension::escapeFilterIsSafe() */
         $twigEscaperFilterIsSafe = static function (Node $filterArgs): array {
-            $expression = iterator_to_array($filterArgs)[0] ?? null;
-
-            if ($expression instanceof ConstantExpression) {
-                $value = $expression->getAttribute('value');
+            foreach ($filterArgs as $arg) {
+                if ($arg instanceof ConstantExpression) {
+                    $value = $arg->getAttribute('value');
+
+                    // Our escaper strategy variants that tolerate input encoding are also safe in
+                    // the original context (e.g. for the filter argument 'contao_html' we will
+                    // return ['contao_html', 'html']).
+                    if (\in_array($value, ['contao_html', 'contao_html_attr'], true)) {
+                        return [$value, substr($value, 7)];
+                    }
 
-                // Our escaper strategy variants that tolerate input encoding are also safe in
-                // the original context (e.g. for the filter argument 'contao_html' we will
-                // return ['contao_html', 'html']).
-                if (\in_array($value, ['contao_html', 'contao_html_attr'], true)) {
-                    return [$value, substr($value, 7)];
+                    return [$value];
                 }
+
+                return [];
             }
 
-            return twig_escape_filter_is_safe($filterArgs);
+            return ['html'];
         };
 
         return [
diff --git a/core-bundle/src/Twig/Interop/ContaoEscaper.php b/core-bundle/src/Twig/Interop/ContaoEscaper.php
index ac7a67a048d..2cdbcc11fb2 100644
--- a/core-bundle/src/Twig/Interop/ContaoEscaper.php
+++ b/core-bundle/src/Twig/Interop/ContaoEscaper.php
@@ -13,7 +13,6 @@
 namespace Contao\CoreBundle\Twig\Interop;
 
 use Contao\StringUtil;
-use Twig\Environment;
 use Twig\Error\RuntimeError;
 
 /**
@@ -33,7 +32,7 @@ final class ContaoEscaper
      *
      * @see twig_escape_filter
      */
-    public function escapeHtml(Environment $environment, mixed $string, string|null $charset): string
+    public function escapeHtml(mixed $string, string|null $charset): string
     {
         if (null !== $charset && 'UTF-8' !== strtoupper($charset)) {
             throw new RuntimeError(sprintf('The "contao_html" escape filter does not support the %s charset, use UTF-8 instead.', $charset));
@@ -50,7 +49,7 @@ public function escapeHtml(Environment $environment, mixed $string, string|null
      *
      * @see twig_escape_filter
      */
-    public function escapeHtmlAttr(Environment $environment, mixed $string, string|null $charset): string
+    public function escapeHtmlAttr(mixed $string, string|null $charset): string
     {
         if (null !== $charset && 'UTF-8' !== strtoupper($charset)) {
             throw new RuntimeError(sprintf('The "contao_html_attr" escape filter does not support the %s charset, use UTF-8 instead.', $charset));
diff --git a/core-bundle/tests/EventListener/StoreRefererListenerTest.php b/core-bundle/tests/EventListener/StoreRefererListenerTest.php
index 06f833f60b7..fb103426201 100644
--- a/core-bundle/tests/EventListener/StoreRefererListenerTest.php
+++ b/core-bundle/tests/EventListener/StoreRefererListenerTest.php
@@ -246,6 +246,7 @@ public function testDoesNotStoreTheRefererIfTheBackEndSessionCannotBeModified():
         $request->setSession($session);
 
         $request->attributes->set('_scope', ContaoCoreBundle::SCOPE_BACKEND);
+        $request->attributes->set('_store_referrer', false);
 
         $listener = $this->getListener($this->createMock(User::class));
         $listener($this->getResponseEvent($request));
diff --git a/core-bundle/tests/Twig/Extension/ContaoExtensionTest.php b/core-bundle/tests/Twig/Extension/ContaoExtensionTest.php
index 0b7d48a3204..cae6f8b7d2b 100644
--- a/core-bundle/tests/Twig/Extension/ContaoExtensionTest.php
+++ b/core-bundle/tests/Twig/Extension/ContaoExtensionTest.php
@@ -176,6 +176,11 @@ public function testIncludeFunctionDelegatesToTwigInclude(): void
     public function testThrowsIfCoreIncludeFunctionIsNotFound(): void
     {
         $environment = $this->createMock(Environment::class);
+        $environment
+            ->method('getRuntime')
+            ->willReturn(new EscaperRuntime())
+        ;
+
         $environment
             ->method('getExtension')
             ->willReturnMap([
@@ -185,14 +190,6 @@ public function testThrowsIfCoreIncludeFunctionIsNotFound(): void
             ])
         ;
 
-        // Forward compatibility with twig/twig >=3.10.0
-        if (class_exists(EscaperRuntime::class)) {
-            $environment
-                ->method('getRuntime')
-                ->willReturn(new EscaperRuntime())
-            ;
-        }
-
         $extension = new ContaoExtension(
             $environment,
             $this->createMock(ContaoFilesystemLoader::class),
@@ -379,46 +376,6 @@ public static function provideTemplateNames(): iterable
         yield 'core-bundle template' => ['@ContaoCore/Image/Studio/figure.html.twig'];
     }
 
-    /**
-     * We need to adjust some of Twig's core functions (e.g. the escape filter) but
-     * still delegate to the original implementation for maximum compatibility. This
-     * test makes sure the function's signatures remains the same and changes to the
-     * original codebase do not stay unnoticed.
-     *
-     * @dataProvider provideTwigFunctionSignatures
-     */
-    public function testContaoUsesCorrectTwigFunctionSignatures(\ReflectionFunction|\ReflectionMethod $reflector, array $expectedParameters): void
-    {
-        $parameters = array_map(
-            static fn (\ReflectionParameter $parameter): array => [
-                ($type = $parameter->getType()) instanceof \ReflectionNamedType ? $type->getName() : null,
-                $parameter->getName(),
-            ],
-            $reflector->getParameters(),
-        );
-
-        $this->assertSame($parameters, $expectedParameters);
-    }
-
-    public static function provideTwigFunctionSignatures(): iterable
-    {
-        // Backwards compatibility with twig/twig <3.9.0
-        new \ReflectionClass(EscaperExtension::class);
-
-        yield [
-            new \ReflectionFunction('twig_escape_filter'),
-            [
-                [Environment::class, 'env'],
-                [null, 'string'],
-                [null, 'strategy'],
-                [null, 'charset'],
-                [null, 'autoescape'],
-            ],
-        ];
-
-        yield [new \ReflectionFunction('twig_escape_filter_is_safe'), [[Node::class, 'filterArgs']]];
-    }
-
     /**
      * @param Environment&MockObject $environment
      */
@@ -427,6 +384,11 @@ private function getContaoExtension(Environment|null $environment = null, Contao
         $environment ??= $this->createMock(Environment::class);
         $filesystemLoader ??= $this->createMock(ContaoFilesystemLoader::class);
 
+        $environment
+            ->method('getRuntime')
+            ->willReturn(new EscaperRuntime())
+        ;
+
         $environment
             ->method('getExtension')
             ->willReturnMap([
@@ -435,14 +397,6 @@ private function getContaoExtension(Environment|null $environment = null, Contao
             ])
         ;
 
-        // Forward compatibility with twig/twig >=3.10.0
-        if (class_exists(EscaperRuntime::class)) {
-            $environment
-                ->method('getRuntime')
-                ->willReturn(new EscaperRuntime())
-            ;
-        }
-
         return new ContaoExtension(
             $environment,
             $filesystemLoader,
diff --git a/core-bundle/tests/Twig/Interop/ContaoEscaperTest.php b/core-bundle/tests/Twig/Interop/ContaoEscaperTest.php
index 270f20ac7b0..7eec2775710 100644
--- a/core-bundle/tests/Twig/Interop/ContaoEscaperTest.php
+++ b/core-bundle/tests/Twig/Interop/ContaoEscaperTest.php
@@ -21,7 +21,6 @@
 use Psr\Log\LoggerInterface;
 use Symfony\Component\HttpFoundation\RequestStack;
 use Symfony\Component\HttpKernel\Fragment\FragmentHandler;
-use Twig\Environment;
 use Twig\Error\RuntimeError;
 
 class ContaoEscaperTest extends TestCase
@@ -140,11 +139,11 @@ public function testEscapeHtmlAttrThrowsErrorIfCharsetIsNotUtf8(): void
 
     private function invokeEscapeHtml(int|string $input, string|null $charset): string
     {
-        return (new ContaoEscaper())->escapeHtml($this->createMock(Environment::class), $input, $charset);
+        return (new ContaoEscaper())->escapeHtml($input, $charset);
     }
 
     private function invokeEscapeHtmlAttr(int|string $input, string|null $charset): string
     {
-        return (new ContaoEscaper())->escapeHtmlAttr($this->createMock(Environment::class), $input, $charset);
+        return (new ContaoEscaper())->escapeHtmlAttr($input, $charset);
     }
 }
diff --git a/core-bundle/tests/Twig/Interop/PhpTemplateParentReferenceNodeTest.php b/core-bundle/tests/Twig/Interop/PhpTemplateParentReferenceNodeTest.php
index cf11c609d46..a2ebe1e31a3 100644
--- a/core-bundle/tests/Twig/Interop/PhpTemplateParentReferenceNodeTest.php
+++ b/core-bundle/tests/Twig/Interop/PhpTemplateParentReferenceNodeTest.php
@@ -14,7 +14,6 @@
 
 use Contao\CoreBundle\Tests\TestCase;
 use Contao\CoreBundle\Twig\Interop\PhpTemplateParentReferenceNode;
-use Twig\Attribute\YieldReady;
 use Twig\Compiler;
 use Twig\Environment;
 
@@ -27,15 +26,10 @@ public function testCompilesParentReferenceCode(): void
         (new PhpTemplateParentReferenceNode())->compile($compiler);
 
         $expectedSource = <<<'SOURCE'
-            echo sprintf('[[TL_PARENT_%s]]', \Contao\CoreBundle\Framework\ContaoFramework::getNonce());
+            yield sprintf('[[TL_PARENT_%s]]', \Contao\CoreBundle\Framework\ContaoFramework::getNonce());
 
             SOURCE;
 
-        // Forward compatibility with twig/twig >=3.9.0
-        if (class_exists(YieldReady::class)) {
-            $expectedSource = str_replace('echo', 'yield', $expectedSource);
-        }
-
         $this->assertSame($expectedSource, $compiler->getSource());
     }
 }
diff --git a/core-bundle/tests/Twig/Interop/PhpTemplateProxyNodeTest.php b/core-bundle/tests/Twig/Interop/PhpTemplateProxyNodeTest.php
index 7edb743ffc3..a2784730cc7 100644
--- a/core-bundle/tests/Twig/Interop/PhpTemplateProxyNodeTest.php
+++ b/core-bundle/tests/Twig/Interop/PhpTemplateProxyNodeTest.php
@@ -15,7 +15,6 @@
 use Contao\CoreBundle\Tests\TestCase;
 use Contao\CoreBundle\Twig\Extension\ContaoExtension;
 use Contao\CoreBundle\Twig\Interop\PhpTemplateProxyNode;
-use Twig\Attribute\YieldReady;
 use Twig\Compiler;
 use Twig\Environment;
 
@@ -28,7 +27,7 @@ public function testCompilesProxyCode(): void
         (new PhpTemplateProxyNode(ContaoExtension::class))->compile($compiler);
 
         $expectedSource = <<<'SOURCE'
-            echo $this->extensions["Contao\\CoreBundle\\Twig\\Extension\\ContaoExtension"]->renderLegacyTemplate(
+            yield $this->extensions["Contao\\CoreBundle\\Twig\\Extension\\ContaoExtension"]->renderLegacyTemplate(
                 $this->getTemplateName(),
                 array_map(
                     function(callable $block) use ($context): string {
@@ -47,11 +46,6 @@ function(callable $block) use ($context): string {
 
             SOURCE;
 
-        // Forward compatibility with twig/twig >=3.9.0
-        if (class_exists(YieldReady::class)) {
-            $expectedSource = str_replace('echo', 'yield', $expectedSource);
-        }
-
         $this->assertSame($expectedSource, $compiler->getSource());
     }
 }
diff --git a/core-bundle/tests/Twig/ResponseContext/AddNodeTest.php b/core-bundle/tests/Twig/ResponseContext/AddNodeTest.php
index 04a8c6cdcff..8fbdc4cac22 100644
--- a/core-bundle/tests/Twig/ResponseContext/AddNodeTest.php
+++ b/core-bundle/tests/Twig/ResponseContext/AddNodeTest.php
@@ -16,7 +16,6 @@
 use Contao\CoreBundle\Twig\Extension\ContaoExtension;
 use Contao\CoreBundle\Twig\ResponseContext\AddNode;
 use Contao\CoreBundle\Twig\ResponseContext\DocumentLocation;
-use Twig\Attribute\YieldReady;
 use Twig\Compiler;
 use Twig\Environment;
 use Twig\Node\Expression\ConstantExpression;
@@ -43,7 +42,7 @@ public function testCompilesAddNode(): void
                 $__contao_document_content = '';
                 foreach((function () use (&$context, $macros, $blocks) {
                     // line 42
-                    echo "foobar";
+                    yield "foobar";
                     yield '';
                 })() as $__contao_document_chunk) {
                     $__contao_document_content .= ob_get_contents() . $__contao_document_chunk;
@@ -56,11 +55,6 @@ public function testCompilesAddNode(): void
 
             SOURCE;
 
-        // Forward compatibility with twig/twig >=3.9.0
-        if (class_exists(YieldReady::class)) {
-            $expectedSource = str_replace('echo', 'yield', $expectedSource);
-        }
-
         $this->assertSame($expectedSource, $compiler->getSource());
     }
 }