diff --git a/core/composer.json b/core/composer.json
index dd5e958..c80c93c 100644
--- a/core/composer.json
+++ b/core/composer.json
@@ -17,7 +17,7 @@
         "symfony/validator": "2.7.*",
         "symfony/process": "2.7.*",
         "symfony/yaml": "2.7.*",
-        "twig/twig": "^1.23.1",
+        "twig/twig": "2.0.x-dev",
         "doctrine/common": "2.5.*",
         "doctrine/annotations": "1.2.*",
         "guzzlehttp/guzzle": "~6.1",
diff --git a/core/lib/Drupal/Core/Template/TwigEnvironment.php b/core/lib/Drupal/Core/Template/TwigEnvironment.php
index 3a3d002..58deff1 100644
--- a/core/lib/Drupal/Core/Template/TwigEnvironment.php
+++ b/core/lib/Drupal/Core/Template/TwigEnvironment.php
@@ -27,6 +27,8 @@ class TwigEnvironment extends \Twig_Environment {
    */
   protected $templateClasses;
 
+  protected $templateClassPrefix = '__TwigTemplate_';
+
   /**
    * Constructs a TwigEnvironment object and stores cache and storage
    * internally.
@@ -43,10 +45,6 @@ class TwigEnvironment extends \Twig_Environment {
    *   The options for the Twig environment.
    */
   public function __construct($root, CacheBackendInterface $cache, $twig_extension_hash, \Twig_LoaderInterface $loader = NULL, $options = array()) {
-    // Ensure that twig.engine is loaded, given that it is needed to render a
-    // template because functions like TwigExtension::escapeFilter() are called.
-    require_once $root . '/core/themes/engines/twig/twig.engine';
-
     $this->templateClasses = array();
 
     $options += array(
@@ -66,8 +64,8 @@ public function __construct($root, CacheBackendInterface $cache, $twig_extension
       $options['cache'] = new TwigPhpStorageCache($cache, $twig_extension_hash);
     }
 
-    $this->loader = $loader;
-    parent::__construct($this->loader, $options);
+    $this->setLoader($loader);
+    parent::__construct($this->getLoader(), $options);
   }
 
   /**
@@ -88,7 +86,7 @@ public function getTemplateClass($name, $index = NULL) {
     // node.html.twig for the output of each node and the same compiled class.
     $cache_index = $name . (NULL === $index ? '' : '_' . $index);
     if (!isset($this->templateClasses[$cache_index])) {
-      $this->templateClasses[$cache_index] = $this->templateClassPrefix . hash('sha256', $this->loader->getCacheKey($name)) . (NULL === $index ? '' : '_' . $index);
+      $this->templateClasses[$cache_index] = $this->templateClassPrefix . hash('sha256', $this->getLoader()->getCacheKey($name)) . (NULL === $index ? '' : '_' . $index);
     }
     return $this->templateClasses[$cache_index];
   }
diff --git a/core/lib/Drupal/Core/Template/TwigExtension.php b/core/lib/Drupal/Core/Template/TwigExtension.php
index 0632db5..676641b 100644
--- a/core/lib/Drupal/Core/Template/TwigExtension.php
+++ b/core/lib/Drupal/Core/Template/TwigExtension.php
@@ -168,7 +168,7 @@ public function getFilters() {
       new \Twig_SimpleFilter('safe_join', [$this, 'safeJoin'], ['needs_environment' => true, 'is_safe' => ['html']]),
 
       // Array filters.
-      new \Twig_SimpleFilter('without', 'twig_without'),
+      new \Twig_SimpleFilter('without', [$this, 'withoutFilter']),
 
       // CSS class and ID filters.
       new \Twig_SimpleFilter('clean_class', '\Drupal\Component\Utility\Html::getClass'),
@@ -557,4 +557,37 @@ public function safeJoin(\Twig_Environment $env, $value, $glue = '') {
     }, (array) $value));
   }
 
+  /**
+   * Removes child elements from a copy of the original array.
+   *
+   * Creates a copy of the renderable array and removes child elements by key
+   * specified through filter's arguments. The copy can be printed without these
+   * elements. The original renderable array is still available and can be used
+   * to print child elements in their entirety in the twig template.
+   *
+   * @param array|object $element
+   *   The parent renderable array to exclude the child items.
+   * @param string[] $args, ...
+   *   The string keys of $element to prevent printing.
+   *
+   * @return array
+   *   The filtered renderable array.
+   */
+  public function withoutFilter($element) {
+    if ($element instanceof \ArrayAccess) {
+      $filtered_element = clone $element;
+    }
+    else {
+      $filtered_element = $element;
+    }
+    $args = func_get_args();
+    unset($args[0]);
+    foreach ($args as $arg) {
+      if (isset($filtered_element[$arg])) {
+        unset($filtered_element[$arg]);
+      }
+    }
+    return $filtered_element;
+  }
+
 }
diff --git a/core/modules/system/src/Tests/Theme/TwigEnvironmentTest.php b/core/modules/system/src/Tests/Theme/TwigEnvironmentTest.php
index 0bc52d0..f818637 100644
--- a/core/modules/system/src/Tests/Theme/TwigEnvironmentTest.php
+++ b/core/modules/system/src/Tests/Theme/TwigEnvironmentTest.php
@@ -120,13 +120,18 @@ public function testCacheFilename() {
     // Note: Later we refetch the twig service in order to bypass its internal
     // static cache.
     $environment = \Drupal::service('twig');
+    $template_path = 'core/modules/system/templates/container.html.twig';
 
-    $original_filename = $environment->getCacheFilename('core/modules/system/templates/container.html.twig');
+    $cache = $environment->getCache();
+    $class = $environment->getTemplateClass($template_path);
+    $original_filename = $cache->generateKey($template_path, $class);
     \Drupal::getContainer()->set('twig', NULL);
 
     \Drupal::service('module_installer')->install(['twig_extension_test']);
     $environment = \Drupal::service('twig');
-    $new_extension_filename = $environment->getCacheFilename('core/modules/system/templates/container.html.twig');
+    $cache = $environment->getCache();
+    $class = $environment->getTemplateClass($template_path);
+    $new_extension_filename = $cache->generateKey($template_path, $class);
     \Drupal::getContainer()->set('twig', NULL);
 
     $this->assertNotEqual($new_extension_filename, $original_filename);
diff --git a/core/modules/system/src/Tests/Theme/TwigSettingsTest.php b/core/modules/system/src/Tests/Theme/TwigSettingsTest.php
index f581fa62..74a517b 100644
--- a/core/modules/system/src/Tests/Theme/TwigSettingsTest.php
+++ b/core/modules/system/src/Tests/Theme/TwigSettingsTest.php
@@ -101,7 +101,11 @@ function testTwigCacheOverride() {
     // theme_test.template_test.html.twig.
     $info = $templates->get('theme_test_template_test');
     $template_filename = $info['path'] . '/' . $info['template'] . $extension;
-    $cache_filename = $this->container->get('twig')->getCacheFilename($template_filename);
+
+    $environment = $this->container->get('twig');
+    $cache = $environment->getCache();
+    $class = $environment->getTemplateClass($template_filename);
+    $cache_filename = $cache->generateKey($template_filename, $class);
 
     // Navigate to the page and make sure the template gets cached.
     $this->drupalGet('theme-test/template-test');
diff --git a/core/modules/system/tests/modules/twig_extension_test/src/TwigExtension/TestExtension.php b/core/modules/system/tests/modules/twig_extension_test/src/TwigExtension/TestExtension.php
index 3c2b851..5383fab 100644
--- a/core/modules/system/tests/modules/twig_extension_test/src/TwigExtension/TestExtension.php
+++ b/core/modules/system/tests/modules/twig_extension_test/src/TwigExtension/TestExtension.php
@@ -7,12 +7,10 @@
 
 namespace Drupal\twig_extension_test\TwigExtension;
 
-use Drupal\Core\Template\TwigExtension;
-
 /**
  * A test Twig extension that adds a custom function and a custom filter.
  */
-class TestExtension extends TwigExtension {
+class TestExtension extends \TwigExtension {
 
   /**
    * Generates a list of all Twig functions that this extension defines.
@@ -27,9 +25,9 @@ class TestExtension extends TwigExtension {
    *   The value is a standard PHP callback that defines what the function does.
    */
   public function getFunctions() {
-    return array(
-      'testfunc' => new \Twig_Function_Function(array('Drupal\twig_extension_test\TwigExtension\TestExtension', 'testFunction')),
-    );
+    return [
+      new \Twig_SimpleFunction('testfunc', [$this, 'testFunction']),
+    ];
   }
 
   /**
@@ -45,9 +43,9 @@ public function getFunctions() {
    *   The value is a standard PHP callback that defines what the filter does.
    */
   public function getFilters() {
-    return array(
-      'testfilter' => new \Twig_Filter_Function(array('Drupal\twig_extension_test\TwigExtension\TestExtension', 'testFilter')),
-    );
+    return [
+      new \Twig_SimpleFilter('testfilter', [$this, 'testFilter']),
+    ];
   }
 
   /**
diff --git a/core/modules/system/tests/modules/twig_extension_test/twig_extension_test.services.yml b/core/modules/system/tests/modules/twig_extension_test/twig_extension_test.services.yml
index 491d1e8..8784c0f 100644
--- a/core/modules/system/tests/modules/twig_extension_test/twig_extension_test.services.yml
+++ b/core/modules/system/tests/modules/twig_extension_test/twig_extension_test.services.yml
@@ -1,6 +1,5 @@
 services:
   twig_extension_test.twig.test_extension:
-    arguments: ['@renderer']
     class: Drupal\twig_extension_test\TwigExtension\TestExtension
     tags:
       - { name: twig.extension }
diff --git a/core/tests/Drupal/Tests/Core/Template/AttributeTest.php b/core/tests/Drupal/Tests/Core/Template/AttributeTest.php
index 69941a9..3f7a5f1 100644
--- a/core/tests/Drupal/Tests/Core/Template/AttributeTest.php
+++ b/core/tests/Drupal/Tests/Core/Template/AttributeTest.php
@@ -12,6 +12,7 @@
 use Drupal\Core\Template\Attribute;
 use Drupal\Core\Template\AttributeArray;
 use Drupal\Core\Template\AttributeString;
+use Drupal\Core\Template\Loader\StringLoader;
 use Drupal\Tests\UnitTestCase;
 use Drupal\Component\Render\MarkupInterface;
 
@@ -268,7 +269,7 @@ public function testChainAddRemoveClasses() {
    * @covers ::addClass
    */
   public function testTwigAddRemoveClasses($template, $expected, $seed_attributes = array()) {
-    $loader = new \Twig_Loader_String();
+    $loader = new StringLoader();
     $twig = new \Twig_Environment($loader);
     $data = array('attributes' => new Attribute($seed_attributes));
     $result = $twig->render($template, $data);
diff --git a/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php b/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
index cb09022..d8adbc7 100644
--- a/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
+++ b/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
@@ -5,7 +5,7 @@
  * Contains \Drupal\Tests\Core\Template\TwigExtensionTest.
  */
 
-namespace Drupal\Tests\Core\Template;
+namespace Drupal\Tests\Core\Template {
 
 use Drupal\Core\Render\RenderableInterface;
 use Drupal\Core\Render\RendererInterface;
@@ -31,11 +31,12 @@ class TwigExtensionTest extends UnitTestCase {
    */
   public function testEscaping($template, $expected) {
     $renderer = $this->getMock('\Drupal\Core\Render\RendererInterface');
-    $twig = new \Twig_Environment(NULL, array(
+    $loader = new \Twig_Loader_Filesystem();
+    $twig = new \Twig_Environment($loader, array(
       'debug' => TRUE,
       'cache' => FALSE,
       'autoescape' => 'html',
-      'optimizations' => 0
+      'optimizations' => 0,
     ));
     $twig->addExtension((new TwigExtension($renderer))->setUrlGenerator($this->getMock('Drupal\Core\Routing\UrlGeneratorInterface')));
 
@@ -97,7 +98,7 @@ public function testActiveTheme() {
       ->willReturn($active_theme);
     $extension->setThemeManager($theme_manager);
 
-    $loader = new \Twig_Loader_String();
+    $loader = new StringLoader();
     $twig = new \Twig_Environment($loader);
     $twig->addExtension($extension);
     $result = $twig->render('{{ active_theme() }}');
@@ -145,7 +146,7 @@ public function testActiveThemePath() {
       ->willReturn($active_theme);
     $extension->setThemeManager($theme_manager);
 
-    $loader = new \Twig_Loader_String();
+    $loader = new StringLoader();
     $twig = new \Twig_Environment($loader);
     $twig->addExtension($extension);
     $result = $twig->render('{{ active_theme_path() }}');
@@ -159,11 +160,12 @@ public function testActiveThemePath() {
    */
   public function testSafeStringEscaping() {
     $renderer = $this->getMock('\Drupal\Core\Render\RendererInterface');
-    $twig = new \Twig_Environment(NULL, array(
+    $loader = new \Twig_Loader_Filesystem();
+    $twig = new \Twig_Environment($loader, array(
       'debug' => TRUE,
       'cache' => FALSE,
       'autoescape' => 'html',
-      'optimizations' => 0
+      'optimizations' => 0,
     ));
     $twig_extension = new TwigExtension($renderer);
 
@@ -242,6 +244,7 @@ public function providerTestRenderVar() {
 
 }
 
+
 class TwigExtensionTestString {
 
   protected $string;
@@ -255,3 +258,15 @@ public function __toString() {
   }
 
 }
+}
+
+namespace {
+  if (!function_exists('t')) {
+    function t($string, array $args = []) {
+      return strtr($string, $args);
+    }
+  }
+  if (!function_exists('file_create_url')) {
+    function file_create_url() {}
+  }
+}
diff --git a/core/themes/engines/twig/twig.engine b/core/themes/engines/twig/twig.engine
index f4e18f5..df1baaa 100644
--- a/core/themes/engines/twig/twig.engine
+++ b/core/themes/engines/twig/twig.engine
@@ -121,35 +121,3 @@ function twig_render_template($template_file, array $variables) {
   return Markup::create(implode('', $output));
 }
 
-/**
- * Removes child elements from a copy of the original array.
- *
- * Creates a copy of the renderable array and removes child elements by key
- * specified through filter's arguments. The copy can be printed without these
- * elements. The original renderable array is still available and can be used
- * to print child elements in their entirety in the twig template.
- *
- * @param array|object $element
- *   The parent renderable array to exclude the child items.
- * @param string[] $args, ...
- *   The string keys of $element to prevent printing.
- *
- * @return array
- *   The filtered renderable array.
- */
-function twig_without($element) {
-  if ($element instanceof ArrayAccess) {
-    $filtered_element = clone $element;
-  }
-  else {
-    $filtered_element = $element;
-  }
-  $args = func_get_args();
-  unset($args[0]);
-  foreach ($args as $arg) {
-    if (isset($filtered_element[$arg])) {
-      unset($filtered_element[$arg]);
-    }
-  }
-  return $filtered_element;
-}