core/lib/Drupal/Core/CoreServiceProvider.php                   |  2 +-
 .../Core/DependencyInjection/Compiler/TwigExtensionPass.php    |  4 +++-
 core/lib/Drupal/Core/Template/TwigEnvironment.php              | 10 +++++-----
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/core/lib/Drupal/Core/CoreServiceProvider.php b/core/lib/Drupal/Core/CoreServiceProvider.php
index 3d1b350..7b83fc2 100644
--- a/core/lib/Drupal/Core/CoreServiceProvider.php
+++ b/core/lib/Drupal/Core/CoreServiceProvider.php
@@ -79,7 +79,7 @@ public function register(ContainerBuilder $container) {
     $container->addCompilerPass(new RegisterStreamWrappersPass());
     $container->addCompilerPass(new GuzzleMiddlewarePass());
 
-    $this->addCompilerPass(new TwigExtensionPass());
+    $container->addCompilerPass(new TwigExtensionPass());
 
     // Add a compiler pass for registering event subscribers.
     $container->addCompilerPass(new RegisterKernelListenersPass(), PassConfig::TYPE_AFTER_REMOVING);
diff --git a/core/lib/Drupal/Core/DependencyInjection/Compiler/TwigExtensionPass.php b/core/lib/Drupal/Core/DependencyInjection/Compiler/TwigExtensionPass.php
index f7ac226..35dd690 100644
--- a/core/lib/Drupal/Core/DependencyInjection/Compiler/TwigExtensionPass.php
+++ b/core/lib/Drupal/Core/DependencyInjection/Compiler/TwigExtensionPass.php
@@ -11,7 +11,9 @@
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 
 /**
- * Adds a hash of all extensions for twig template invalidation.
+ * Adds twig_extension_hash parameter to the container.
+ *
+ * A hash of all extensions for Twig template invalidation.
  */
 class TwigExtensionPass implements CompilerPassInterface {
 
diff --git a/core/lib/Drupal/Core/Template/TwigEnvironment.php b/core/lib/Drupal/Core/Template/TwigEnvironment.php
index fbc14bf..b86a40a 100644
--- a/core/lib/Drupal/Core/Template/TwigEnvironment.php
+++ b/core/lib/Drupal/Core/Template/TwigEnvironment.php
@@ -31,7 +31,7 @@ class TwigEnvironment extends \Twig_Environment {
   protected $cache_object = NULL;
 
   /**
-   * The phpstorage object used for storing the templates.
+   * The PhpStorage object used for storing the templates.
    *
    * @var \Drupal\Core\PhpStorage\PhpStorageFactory
    */
@@ -52,7 +52,7 @@ class TwigEnvironment extends \Twig_Environment {
   protected $templateClasses;
 
   /**
-   * The twig extension hash, which is used to invalidate twig templates.
+   * The Twig extension hash, which is used to invalidate Twig templates.
    *
    * @var string
    */
@@ -67,7 +67,7 @@ class TwigEnvironment extends \Twig_Environment {
    * @param \Drupal\Core\Cache\CacheBackendInterface $cache
    *   The cache bin.
    * @param string $twig_extension_hash
-   *   The twig extension hash.
+   *   The Twig extension hash.
    * @param \Twig_LoaderInterface $loader
    *   The Twig loader or loader chain.
    * @param array $options
@@ -123,8 +123,8 @@ public function updateCompiledTemplate($cache_filename, $name) {
    */
   public function getCacheFilename($name) {
     // We override the cache filename in order to avoid issues with not using
-    // shared filesystems. The twig templates for example rely on available
-    // twig extensions, so we need to take into account the \Drupal::VERSION
+    // shared filesystems. The Twig templates for example rely on available Twig
+    // extensions, so we need to take into account the \Drupal::VERSION
     // deployment identifier, much like for the container itself.
 
     if (!$this->cache) {