diff --git a/core/lib/Drupal/Core/Form/EventSubscriber/FormAjaxSubscriber.php b/core/lib/Drupal/Core/Form/EventSubscriber/FormAjaxSubscriber.php
index 4d2d8fa86e4c87a0d2893f59552eadc219dc5c40..cae43980274a0c57cf1d1e9500bad79567f24fb4 100644
--- a/core/lib/Drupal/Core/Form/EventSubscriber/FormAjaxSubscriber.php
+++ b/core/lib/Drupal/Core/Form/EventSubscriber/FormAjaxSubscriber.php
@@ -92,7 +92,7 @@ public function onException(GetResponseForExceptionEvent $event) {
       $form_state = $exception->getFormState();
 
       // Set the build ID from the request as the old build ID on the form.
-      $form['#build_id_old'] = $request->get('form_build_id');
+      $form['#build_id_old'] = $request->request->get('form_build_id');
 
       try {
         $response = $this->formAjaxResponseBuilder->buildResponse($request, $form, $form_state, []);
diff --git a/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php b/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php
index 2ff8bb7660d278c6718cd9ebbf17cfa251fb0c66..e3864610f4f96013abb73064398e1e75a396ce2a 100644
--- a/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php
+++ b/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php
@@ -80,7 +80,7 @@ public function registerFormat($format, $mime_type) {
   protected function getContentType(Request $request) {
     // AJAX iframe uploads need special handling, because they contain a JSON
     // response wrapped in <textarea>.
-    if ($request->get('ajax_iframe_upload', FALSE)) {
+    if ($request->request->get('ajax_iframe_upload', FALSE)) {
       return 'iframeupload';
     }
 
diff --git a/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php
index 53d80c83e6d6f2d4c2fd582b22df1836436f3fe2..78edb896453d19e8be4551acfd4bc781de8ffccf 100644
--- a/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php
+++ b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php
@@ -91,7 +91,7 @@ public static function create(ContainerInterface $container, array $configuratio
    * {@inheritdoc}
    */
   public function getLangcode(Request $request = NULL) {
-    $langcode = $request->get(static::QUERY_PARAMETER);
+    $langcode = $request->query->get(static::QUERY_PARAMETER);
 
     $language_enabled = array_key_exists($langcode, $this->languageManager->getLanguages());
     return $language_enabled ? $langcode : NULL;
diff --git a/core/modules/search/src/Controller/SearchController.php b/core/modules/search/src/Controller/SearchController.php
index 06bab2d89181391d12700d8023e2f77b2f4fc7dd..3460c32068c1f25bd4084aeb3df544d189cac276 100644
--- a/core/modules/search/src/Controller/SearchController.php
+++ b/core/modules/search/src/Controller/SearchController.php
@@ -79,7 +79,7 @@ public function view(Request $request, SearchPageInterface $entity) {
     // and we don't want to build the results based on last time's request.
     $build['#cache']['contexts'][] = 'url.query_args:keys';
     if ($request->query->has('keys')) {
-      $keys = trim($request->get('keys'));
+      $keys = trim($request->query->get('keys'));
       $plugin->setSearch($keys, $request->query->all(), $request->attributes->all());
     }
 
diff --git a/core/modules/system/src/Controller/ThemeController.php b/core/modules/system/src/Controller/ThemeController.php
index 741dc174e8d1a4b9d60068af041571edf08ea6e6..e1353561ddbdf6b9cc706b3149834259b5ee3cd0 100644
--- a/core/modules/system/src/Controller/ThemeController.php
+++ b/core/modules/system/src/Controller/ThemeController.php
@@ -60,7 +60,7 @@ public static function create(ContainerInterface $container) {
    *   the token is invalid.
    */
   public function uninstall(Request $request) {
-    $theme = $request->get('theme');
+    $theme = $request->query->get('theme');
     $config = $this->config('system.theme');
 
     if (isset($theme)) {
@@ -102,7 +102,7 @@ public function uninstall(Request $request) {
    *   the token is invalid.
    */
   public function install(Request $request) {
-    $theme = $request->get('theme');
+    $theme = $request->query->get('theme');
 
     if (isset($theme)) {
       try {
diff --git a/core/rebuild.php b/core/rebuild.php
index ccd4976e9a786fc6e6ea1b51f28991d3435f320d..4e69eabf655faba696bea70ab9c754624e143dc0 100644
--- a/core/rebuild.php
+++ b/core/rebuild.php
@@ -38,9 +38,9 @@
 }
 
 if (Settings::get('rebuild_access', FALSE) ||
-  ($request->get('token') && $request->get('timestamp') &&
-    ((REQUEST_TIME - $request->get('timestamp')) < 300) &&
-    Crypt::hashEquals(Crypt::hmacBase64($request->get('timestamp'), Settings::get('hash_salt')), $request->get('token'))
+  ($request->query->get('token') && $request->query->get('timestamp') &&
+    ((REQUEST_TIME - $request->query->get('timestamp')) < 300) &&
+    Crypt::hashEquals(Crypt::hmacBase64($request->query->get('timestamp'), Settings::get('hash_salt')), $request->query->get('token'))
   )) {
   // Clear the APCu cache to ensure APCu class loader is reset.
   if (function_exists('apcu_clear_cache')) {
diff --git a/core/tests/Drupal/Tests/Core/StackMiddleware/NegotiationMiddlewareTest.php b/core/tests/Drupal/Tests/Core/StackMiddleware/NegotiationMiddlewareTest.php
index 593ce606d6012a9e642b2a89318154560b22722b..0f5142c94590bae85c23eaf27c90f03943d845e3 100644
--- a/core/tests/Drupal/Tests/Core/StackMiddleware/NegotiationMiddlewareTest.php
+++ b/core/tests/Drupal/Tests/Core/StackMiddleware/NegotiationMiddlewareTest.php
@@ -46,7 +46,7 @@ protected function setUp() {
    */
   public function testAjaxIframeUpload() {
     $request = new Request();
-    $request->attributes->set('ajax_iframe_upload', '1');
+    $request->request->set('ajax_iframe_upload', '1');
 
     $this->assertSame('iframeupload', $this->contentNegotiation->getContentType($request));
   }
@@ -101,9 +101,11 @@ public function testHandle() {
     $request->setRequestFormat('html')->shouldBeCalled();
 
     // Some getContentType calls we don't really care about but have to mock.
-    $request->get('ajax_iframe_upload', FALSE)->shouldBeCalled();
+    $request_data = $this->prophesize(ParameterBag::class);
+    $request_data->get('ajax_iframe_upload', FALSE)->shouldBeCalled();
     $request_mock = $request->reveal();
     $request_mock->query = new ParameterBag([]);
+    $request_mock->request = $request_data->reveal();
 
     // Calling kernel app with default arguments.
     $this->app->handle($request_mock, HttpKernelInterface::MASTER_REQUEST, TRUE)
@@ -126,9 +128,11 @@ public function testSetFormat() {
 
     // Some calls we don't care about.
     $request->setRequestFormat('html')->shouldBeCalled();
-    $request->get('ajax_iframe_upload', FALSE)->shouldBeCalled();
+    $request_data = $this->prophesize(ParameterBag::class);
+    $request_data->get('ajax_iframe_upload', FALSE)->shouldBeCalled();
     $request_mock = $request->reveal();
     $request_mock->query = new ParameterBag([]);
+    $request_mock->request = $request_data->reveal();
 
     // Trigger handle.
     $this->contentNegotiation->registerFormat('david', 'geeky/david');