diff --git a/core/lib/Drupal/Core/StackMiddleware/PageCache.php b/core/lib/Drupal/Core/StackMiddleware/PageCache.php
index d4ec291..f8a6aa4 100644
--- a/core/lib/Drupal/Core/StackMiddleware/PageCache.php
+++ b/core/lib/Drupal/Core/StackMiddleware/PageCache.php
@@ -323,6 +323,12 @@ protected function getCacheId(Request $request) {
       $request->getUri(),
       $request->getRequestFormat(),
     );
+    $header_contexts = explode(' ', $response->headers->get('X-Drupal-Cache-Contexts'));
+    if (!empty($header_contexts)) {
+      $contexts = $this->cacheContexts->convertTokensToKeys($header_contexts);
+      $cid_parts = array_merge($cid_parts, $contexts);
+    }
+
     return implode(':', $cid_parts);
   }
 
diff --git a/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationBrowser.php b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationBrowser.php
index 9acd295..af36c75 100644
--- a/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationBrowser.php
+++ b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationBrowser.php
@@ -17,7 +17,6 @@
  * @Plugin(
  *   id = \Drupal\language\Plugin\LanguageNegotiation\LanguageNegotiationBrowser::METHOD_ID,
  *   weight = -2,
- *   cache = 0,
  *   name = @Translation("Browser"),
  *   description = @Translation("Language from the browser's language settings."),
  *   config_route_name = "language.negotiation_browser"
@@ -36,6 +35,11 @@ class LanguageNegotiationBrowser extends LanguageNegotiationMethodBase {
   public function getLangcode(Request $request = NULL) {
     $langcode = NULL;
 
+    // Whenever browser-based language negotiation is used, the page cannot be
+    // cached by reverse proxies.
+    // @todo Solve more elegantly in https://www.drupal.org/node/2430335.
+    \Drupal::service('page_cache_kill_switch')->trigger();
+
     if ($this->languageManager && $request && $request->server->get('HTTP_ACCEPT_LANGUAGE')) {
       $http_accept_language = $request->server->get('HTTP_ACCEPT_LANGUAGE');
       $langcodes = array_keys($this->languageManager->getLanguages());
diff --git a/core/modules/system/config/install/system.performance.yml b/core/modules/system/config/install/system.performance.yml
index 1e75b4b..98f34f0 100644
--- a/core/modules/system/config/install/system.performance.yml
+++ b/core/modules/system/config/install/system.performance.yml
@@ -1,6 +1,6 @@
 cache:
   page:
-    use_internal: false
+    use_internal: true
     max_age: 0
 css:
   preprocess: true
diff --git a/core/modules/system/src/Tests/Session/SessionTest.php b/core/modules/system/src/Tests/Session/SessionTest.php
index 0921f66..75b194a 100644
--- a/core/modules/system/src/Tests/Session/SessionTest.php
+++ b/core/modules/system/src/Tests/Session/SessionTest.php
@@ -141,7 +141,11 @@ function testDataPersistence() {
    * Test that empty anonymous sessions are destroyed.
    */
   function testEmptyAnonymousSession() {
-    // Verify that no session is automatically created for anonymous user.
+    // Verify that no session is automatically created for anonymous user when
+    // page caching is disabled.
+    $config = $this->config('system.performance');
+    $config->set('cache.page.use_internal', 0);
+    $config->save();
     $this->drupalGet('');
     $this->assertSessionCookie(FALSE);
     $this->assertSessionEmpty(TRUE);
diff --git a/core/modules/system/src/Tests/System/CronRunTest.php b/core/modules/system/src/Tests/System/CronRunTest.php
index de8cdcc..e17bbf3 100644
--- a/core/modules/system/src/Tests/System/CronRunTest.php
+++ b/core/modules/system/src/Tests/System/CronRunTest.php
@@ -49,6 +49,12 @@ function testCronRun() {
    * need the exact time when cron is triggered.
    */
   function testAutomaticCron() {
+    // Test with a logged in user; anonymous users likely don't cause Drupal to
+    // fully bootstrap, because of the internal page cache or an external
+    // reverse proxy. Reuse this user for disabling cron later in the test.
+    $admin_user = $this->drupalCreateUser(array('administer site configuration'));
+    $this->drupalLogin($admin_user);
+
     // Ensure cron does not run when the cron threshold is enabled and was
     // not passed.
     $cron_last = time();
@@ -68,8 +74,6 @@ function testAutomaticCron() {
     $this->assertTrue($cron_last < \Drupal::state()->get('system.cron_last'), 'Cron runs when the cron threshold is passed.');
 
     // Disable the cron threshold through the interface.
-    $admin_user = $this->drupalCreateUser(array('administer site configuration'));
-    $this->drupalLogin($admin_user);
     $this->drupalPostForm('admin/config/system/cron', array('cron_safe_threshold' => 0), t('Save configuration'));
     $this->assertText(t('The configuration options have been saved.'));
     $this->drupalLogout();
diff --git a/core/modules/user/user.routing.yml b/core/modules/user/user.routing.yml
index 6eb709f..6dc4fdb 100644
--- a/core/modules/user/user.routing.yml
+++ b/core/modules/user/user.routing.yml
@@ -5,6 +5,9 @@ user.register:
     _title: 'Create new account'
   requirements:
     _access_user_register: 'TRUE'
+  # @todo Remove when https://www.drupal.org/node/2465053 lands.
+  options:
+    no_cache: TRUE
 
 user.logout:
   path: '/user/logout'
diff --git a/core/modules/views/src/Tests/GlossaryTest.php b/core/modules/views/src/Tests/GlossaryTest.php
index 2418887..7b1ecac 100644
--- a/core/modules/views/src/Tests/GlossaryTest.php
+++ b/core/modules/views/src/Tests/GlossaryTest.php
@@ -70,10 +70,20 @@ public function testGlossaryView() {
     // Enable the glossary to be displayed.
     $view->storage->enable()->save();
     $this->container->get('router.builder')->rebuildIfNeeded();
+    $url = Url::fromRoute('view.glossary.page_1');
+
+    // Verify cache tags.
+    $this->assertPageCacheContextsAndTags($url, ['languages:' . LanguageInterface::TYPE_CONTENT, 'languages:' . LanguageInterface::TYPE_INTERFACE, 'theme', 'url', 'user.node_grants:view', 'user.permissions'], [
+      'config:views.view.glossary',
+      'node:' . $nodes_by_char['a'][0]->id(), 'node:' . $nodes_by_char['a'][1]->id(), 'node:' . $nodes_by_char['a'][2]->id(),
+      'node_list',
+      'user_list',
+      'rendered',
+    ]);
+
     // Check the actual page response.
-    $this->drupalGet('glossary');
+    $this->drupalGet($url);
     $this->assertResponse(200);
-
     foreach ($nodes_per_char as $char => $count) {
       $href = Url::fromRoute('view.glossary.page_1', ['arg_0' => $char])->toString();
       $label = Unicode::strtoupper($char);
@@ -85,16 +95,6 @@ public function testGlossaryView() {
       $result_count = trim(str_replace(array('|', '(', ')'), '', (string) $result[0]));
       $this->assertEqual($result_count, $count, 'The expected number got rendered.');
     }
-
-    // Verify cache tags.
-    $this->enablePageCaching();
-    $this->assertPageCacheContextsAndTags(Url::fromRoute('view.glossary.page_1'), ['languages:' . LanguageInterface::TYPE_CONTENT, 'languages:' . LanguageInterface::TYPE_INTERFACE, 'theme', 'url', 'user.node_grants:view', 'user.permissions'], [
-      'config:views.view.glossary',
-      'node:' . $nodes_by_char['a'][0]->id(), 'node:' . $nodes_by_char['a'][1]->id(), 'node:' . $nodes_by_char['a'][2]->id(),
-      'node_list',
-      'user_list',
-      'rendered',
-    ]);
   }
 
 }
diff --git a/core/modules/views/src/Tests/Plugin/AccessTest.php b/core/modules/views/src/Tests/Plugin/AccessTest.php
index 4bc77db..715ebd5 100644
--- a/core/modules/views/src/Tests/Plugin/AccessTest.php
+++ b/core/modules/views/src/Tests/Plugin/AccessTest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\views\Tests\Plugin;
 
+use Drupal\Core\Cache\Cache;
 use Drupal\views\Tests\ViewTestData;
 use Drupal\views\Views;
 
@@ -101,6 +102,14 @@ function testStaticAccessPlugin() {
     // termination event fires. Simulate that here.
     $this->container->get('router.builder')->rebuildIfNeeded();
 
+    // Clear the page cache.
+    // @todo Remove this. The root cause is that the access plugins alters the
+    //   route's access requirements. That means that the 403 from above does
+    //   not have any cache tags, so modifying the View entity does not cause
+    //   the cached 403 page to be invalidated.
+    //   Remove as part of https://www.drupal.org/node/2464657.
+    Cache::invalidateTags(['rendered']);
+
     $this->assertTrue($access_plugin->access($this->normalUser));
 
     $this->drupalGet('test_access_static');
diff --git a/sites/example.settings.local.php b/sites/example.settings.local.php
index 7859fe5..4cc2109 100644
--- a/sites/example.settings.local.php
+++ b/sites/example.settings.local.php
@@ -28,7 +28,7 @@
 $config['system.performance']['js']['preprocess'] = FALSE;
 
 /**
- * Disable the render cache.
+ * Disable the render cache (this includes the page cache).
  *
  * This setting disables the render cache by using the Null cache back-end
  * defined by the development.services.yml file above.