diff --git a/core/composer.json b/core/composer.json
index 5befb3c..74fb485 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": "~1.22",
+    "twig/twig": "1.x-dev",
     "doctrine/common": "2.5.*",
     "doctrine/annotations": "1.2.*",
     "guzzlehttp/guzzle": "~6.1",
diff --git a/core/composer.lock b/core/composer.lock
index 5563e7e..75480fc 100644
--- a/core/composer.lock
+++ b/core/composer.lock
@@ -4,8 +4,8 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "hash": "e917b58b5b2a847270d4bd49b0bcb22e",
-    "content-hash": "bbb9004b899df99873971591682b1e42",
+    "hash": "b8e9a41fa3316331ae6ce595a9eaec6e",
+    "content-hash": "0c460577ec3b4120d721bdb346a642d2",
     "packages": [
         {
             "name": "doctrine/annotations",
@@ -1779,16 +1779,16 @@
         },
         {
             "name": "twig/twig",
-            "version": "v1.22.1",
+            "version": "1.x-dev",
             "source": {
                 "type": "git",
                 "url": "https://github.com/twigphp/Twig.git",
-                "reference": "b7fc2469fa009897871fb95b68237286fc54a5ad"
+                "reference": "821464ad0137909bb38ad5dbf8a1f2230f33a9f2"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/twigphp/Twig/zipball/b7fc2469fa009897871fb95b68237286fc54a5ad",
-                "reference": "b7fc2469fa009897871fb95b68237286fc54a5ad",
+                "url": "https://api.github.com/repos/twigphp/Twig/zipball/821464ad0137909bb38ad5dbf8a1f2230f33a9f2",
+                "reference": "821464ad0137909bb38ad5dbf8a1f2230f33a9f2",
                 "shasum": ""
             },
             "require": {
@@ -1836,7 +1836,7 @@
             "keywords": [
                 "templating"
             ],
-            "time": "2015-09-15 06:50:16"
+            "time": "2015-09-21 07:07:22"
         },
         {
             "name": "zendframework/zend-diactoros",
@@ -3373,6 +3373,7 @@
     "aliases": [],
     "minimum-stability": "dev",
     "stability-flags": {
+        "twig/twig": 20,
         "behat/mink-goutte-driver": 20
     },
     "prefer-stable": true,
diff --git a/core/lib/Drupal/Core/Template/TwigEnvironment.php b/core/lib/Drupal/Core/Template/TwigEnvironment.php
index 2deec5f..845f219 100644
--- a/core/lib/Drupal/Core/Template/TwigEnvironment.php
+++ b/core/lib/Drupal/Core/Template/TwigEnvironment.php
@@ -68,56 +68,6 @@ public function __construct($root, CacheBackendInterface $cache, $twig_extension
   }
 
   /**
-   * Implements Twig_Environment::loadTemplate().
-   *
-   * We need to overwrite this function to integrate with drupal_php_storage().
-   *
-   * This is a straight copy from loadTemplate() changed to use
-   * drupal_php_storage().
-   *
-   * @param string $name
-   *   The template name or the string which should be rendered as template.
-   * @param int $index
-   *   The index if it is an embedded template.
-   *
-   * @return \Twig_TemplateInterface
-   *   A template instance representing the given template name.
-   *
-   * @throws \Twig_Error_Loader
-   *   When the template cannot be found.
-   * @throws \Twig_Error_Syntax
-   *   When an error occurred during compilation.
-   */
-  public function loadTemplate($name, $index = NULL) {
-    $cls = $this->getTemplateClass($name, $index);
-
-    if (isset($this->loadedTemplates[$cls])) {
-      return $this->loadedTemplates[$cls];
-    }
-
-    if (!class_exists($cls, FALSE)) {
-      $key = $this->cache->generateKey($name, $cls);
-
-      if (!$this->cache->has($key) || ($this->isAutoReload() && !$this->isTemplateFresh($name, $this->cache->getTimestamp($key)))) {
-        $this->cache->write($key, $this->compileSource($this->getLoader()->getSource($name), $name));
-      }
-
-      $this->cache->load($key);
-
-      if (!class_exists($cls, FALSE)) {
-        $compiled_source = $this->compileSource($this->loader->getSource($name), $name);
-        eval('?' . '>' . $compiled_source);
-      }
-    }
-
-    if (!$this->runtimeInitialized) {
-        $this->initRuntime();
-    }
-
-    return $this->loadedTemplates[$cls] = new $cls($this);
-  }
-
-  /**
    * Gets the template class associated with the given string.
    *
    * @param string $name
diff --git a/core/lib/Drupal/Core/Template/TwigPhpStorageCache.php b/core/lib/Drupal/Core/Template/TwigPhpStorageCache.php
index 258aa36..4f5e6b1 100644
--- a/core/lib/Drupal/Core/Template/TwigPhpStorageCache.php
+++ b/core/lib/Drupal/Core/Template/TwigPhpStorageCache.php
@@ -81,13 +81,6 @@ public function generateKey($name, $className) {
   /**
    * {@inheritdoc}
    */
-  public function has($key) {
-    return $this->storage()->exists($key);
-  }
-
-  /**
-   * {@inheritdoc}
-   */
   public function load($key) {
     $this->storage()->load($key);
   }
diff --git a/core/vendor/composer/installed.json b/core/vendor/composer/installed.json
index 0655b5b..aba1783 100644
--- a/core/vendor/composer/installed.json
+++ b/core/vendor/composer/installed.json
@@ -3418,17 +3418,17 @@
     },
     {
         "name": "twig/twig",
-        "version": "v1.22.1",
-        "version_normalized": "1.22.1.0",
+        "version": "1.x-dev",
+        "version_normalized": "1.9999999.9999999.9999999-dev",
         "source": {
             "type": "git",
             "url": "https://github.com/twigphp/Twig.git",
-            "reference": "b7fc2469fa009897871fb95b68237286fc54a5ad"
+            "reference": "821464ad0137909bb38ad5dbf8a1f2230f33a9f2"
         },
         "dist": {
             "type": "zip",
-            "url": "https://api.github.com/repos/twigphp/Twig/zipball/b7fc2469fa009897871fb95b68237286fc54a5ad",
-            "reference": "b7fc2469fa009897871fb95b68237286fc54a5ad",
+            "url": "https://api.github.com/repos/twigphp/Twig/zipball/821464ad0137909bb38ad5dbf8a1f2230f33a9f2",
+            "reference": "821464ad0137909bb38ad5dbf8a1f2230f33a9f2",
             "shasum": ""
         },
         "require": {
@@ -3438,7 +3438,7 @@
             "symfony/debug": "~2.7",
             "symfony/phpunit-bridge": "~2.7"
         },
-        "time": "2015-09-15 06:50:16",
+        "time": "2015-09-21 07:07:22",
         "type": "library",
         "extra": {
             "branch-alias": {
diff --git a/core/vendor/twig/twig/CHANGELOG b/core/vendor/twig/twig/CHANGELOG
index 7e33437..8163a13 100644
--- a/core/vendor/twig/twig/CHANGELOG
+++ b/core/vendor/twig/twig/CHANGELOG
@@ -1,3 +1,7 @@
+* 1.22.2 (2015-XX-XX)
+
+ * fixed a race condition in template loading
+
 * 1.22.1 (2015-09-15)
 
  * fixed regression in template_from_string
diff --git a/core/vendor/twig/twig/ext/twig/php_twig.h b/core/vendor/twig/twig/ext/twig/php_twig.h
index 50f5b45..258ab2f 100644
--- a/core/vendor/twig/twig/ext/twig/php_twig.h
+++ b/core/vendor/twig/twig/ext/twig/php_twig.h
@@ -15,7 +15,7 @@
 #ifndef PHP_TWIG_H
 #define PHP_TWIG_H
 
-#define PHP_TWIG_VERSION "1.22.1"
+#define PHP_TWIG_VERSION "1.22.2-DEV"
 
 #include "php.h"
 
diff --git a/core/vendor/twig/twig/lib/Twig/Cache/Filesystem.php b/core/vendor/twig/twig/lib/Twig/Cache/Filesystem.php
index c33fa90..2e1c0a0 100644
--- a/core/vendor/twig/twig/lib/Twig/Cache/Filesystem.php
+++ b/core/vendor/twig/twig/lib/Twig/Cache/Filesystem.php
@@ -19,7 +19,7 @@ class Twig_Cache_Filesystem implements Twig_CacheInterface
     const FORCE_BYTECODE_INVALIDATION = 1;
 
     private $directory;
-    private $invalidateBytecode;
+    private $options;
 
     /**
      * @param $directory string The root cache directory
@@ -44,17 +44,9 @@ public function generateKey($name, $className)
     /**
      * {@inheritdoc}
      */
-    public function has($key)
-    {
-        return is_file($key);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
     public function load($key)
     {
-        require_once $key;
+        @include_once $key;
     }
 
     /**
@@ -64,11 +56,8 @@ public function write($key, $content)
     {
         $dir = dirname($key);
         if (!is_dir($dir)) {
-            if (false === @mkdir($dir, 0777, true)) {
-                clearstatcache(false, $dir);
-                if (!is_dir($dir)) {
-                    throw new RuntimeException(sprintf('Unable to create the cache directory (%s).', $dir));
-                }
+            if (false === @mkdir($dir, 0777, true) && !is_dir($dir)) {
+                throw new RuntimeException(sprintf('Unable to create the cache directory (%s).', $dir));
             }
         } elseif (!is_writable($dir)) {
             throw new RuntimeException(sprintf('Unable to write in the cache directory (%s).', $dir));
@@ -98,6 +87,6 @@ public function write($key, $content)
      */
     public function getTimestamp($key)
     {
-        return filemtime($key);
+        return (int) @filemtime($key);
     }
 }
diff --git a/core/vendor/twig/twig/lib/Twig/Cache/Null.php b/core/vendor/twig/twig/lib/Twig/Cache/Null.php
index 918e4ce..fde8c80 100644
--- a/core/vendor/twig/twig/lib/Twig/Cache/Null.php
+++ b/core/vendor/twig/twig/lib/Twig/Cache/Null.php
@@ -27,17 +27,8 @@ public function generateKey($name, $className)
     /**
      * {@inheritdoc}
      */
-    public function has($key)
-    {
-        return false;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
     public function write($key, $content)
     {
-        eval('?>'.$content);
     }
 
     /**
@@ -52,7 +43,6 @@ public function load($key)
      */
     public function getTimestamp($key)
     {
-        // never called as has() always returns false
         return 0;
     }
 }
diff --git a/core/vendor/twig/twig/lib/Twig/CacheInterface.php b/core/vendor/twig/twig/lib/Twig/CacheInterface.php
index fedd366..9b17e0f 100644
--- a/core/vendor/twig/twig/lib/Twig/CacheInterface.php
+++ b/core/vendor/twig/twig/lib/Twig/CacheInterface.php
@@ -31,15 +31,6 @@
     public function generateKey($name, $className);
 
     /**
-     * Checks if the cache key exists.
-     *
-     * @param string $key The cache key
-     *
-     * @return bool true if the cache key exists, false otherwise
-     */
-    public function has($key);
-
-    /**
      * Writes the compiled template to cache.
      *
      * @param string $key     The cache key
diff --git a/core/vendor/twig/twig/lib/Twig/Environment.php b/core/vendor/twig/twig/lib/Twig/Environment.php
index cd167bd..5d4c4cf 100644
--- a/core/vendor/twig/twig/lib/Twig/Environment.php
+++ b/core/vendor/twig/twig/lib/Twig/Environment.php
@@ -16,7 +16,7 @@
  */
 class Twig_Environment
 {
-    const VERSION = '1.22.1';
+    const VERSION = '1.22.2-DEV';
 
     protected $charset;
     protected $loader;
@@ -375,15 +375,20 @@ public function loadTemplate($name, $index = null)
                 $key = $this->cache->generateKey($name, $cls);
             }
 
-            if (!$this->cache->has($key) || ($this->isAutoReload() && !$this->isTemplateFresh($name, $this->cache->getTimestamp($key)))) {
+            if (!$this->isAutoReload() || $this->isTemplateFresh($name, $this->cache->getTimestamp($key))) {
+                $this->cache->load($key);
+            }
+
+            if (!class_exists($cls, false)) {
+                $content = $this->compileSource($this->getLoader()->getSource($name), $name);
                 if ($this->bcWriteCacheFile) {
-                    $this->writeCacheFile($key, $this->compileSource($this->getLoader()->getSource($name), $name));
+                    $this->writeCacheFile($key, $content);
                 } else {
-                    $this->cache->write($key, $this->compileSource($this->getLoader()->getSource($name), $name));
+                    $this->cache->write($key, $content);
                 }
-            }
 
-            $this->cache->load($key);
+                eval('?>'.$content);
+            }
         }
 
         if (!$this->runtimeInitialized) {
diff --git a/core/vendor/twig/twig/lib/Twig/Extension/Core.php b/core/vendor/twig/twig/lib/Twig/Extension/Core.php
index 3716f02..f9ec2a4 100644
--- a/core/vendor/twig/twig/lib/Twig/Extension/Core.php
+++ b/core/vendor/twig/twig/lib/Twig/Extension/Core.php
@@ -885,6 +885,9 @@ function twig_split_filter(Twig_Environment $env, $value, $delimiter, $limit = n
 // The '_default' filter is used internally to avoid using the ternary operator
 // which costs a lot for big contexts (before PHP 5.4). So, on average,
 // a function call is cheaper.
+/**
+ * @internal
+ */
 function _twig_default_filter($value, $default = '')
 {
     if (twig_test_empty($value)) {
@@ -982,7 +985,9 @@ function twig_sort_filter($array)
     return $array;
 }
 
-/* used internally */
+/**
+ * @internal
+ */
 function twig_in_filter($value, $compare)
 {
     if (is_array($compare)) {
@@ -1150,7 +1155,9 @@ function twig_escape_filter(Twig_Environment $env, $string, $strategy = 'html',
     }
 }
 
-/* used internally */
+/**
+ * @internal
+ */
 function twig_escape_filter_is_safe(Twig_Node $filterArgs)
 {
     foreach ($filterArgs as $arg) {
@@ -1396,7 +1403,9 @@ function twig_capitalize_string_filter(Twig_Environment $env, $string)
     }
 }
 
-/* used internally */
+/**
+ * @internal
+ */
 function twig_ensure_traversable($seq)
 {
     if ($seq instanceof Traversable || is_array($seq)) {
diff --git a/core/vendor/twig/twig/lib/Twig/Extension/Staging.php b/core/vendor/twig/twig/lib/Twig/Extension/Staging.php
index 8ab0f45..583e6a9 100644
--- a/core/vendor/twig/twig/lib/Twig/Extension/Staging.php
+++ b/core/vendor/twig/twig/lib/Twig/Extension/Staging.php
@@ -15,6 +15,8 @@
  * This class is used by Twig_Environment as a staging area and must not be used directly.
  *
  * @author Fabien Potencier <fabien@symfony.com>
+ *
+ * @internal
  */
 class Twig_Extension_Staging extends Twig_Extension
 {
diff --git a/core/vendor/twig/twig/lib/Twig/Loader/String.php b/core/vendor/twig/twig/lib/Twig/Loader/String.php
index 9bfd856..00f507a 100644
--- a/core/vendor/twig/twig/lib/Twig/Loader/String.php
+++ b/core/vendor/twig/twig/lib/Twig/Loader/String.php
@@ -23,6 +23,8 @@
  *
  * @deprecated since 1.18.1 (to be removed in 2.0)
  *
+ * @internal
+ *
  * @author Fabien Potencier <fabien@symfony.com>
  */
 class Twig_Loader_String implements Twig_LoaderInterface, Twig_ExistsLoaderInterface
diff --git a/core/vendor/twig/twig/lib/Twig/Template.php b/core/vendor/twig/twig/lib/Twig/Template.php
index 36d4162..a816022 100644
--- a/core/vendor/twig/twig/lib/Twig/Template.php
+++ b/core/vendor/twig/twig/lib/Twig/Template.php
@@ -61,6 +61,8 @@ public function getEnvironment()
      * @param array $context
      *
      * @return Twig_TemplateInterface|false The parent template or false if there is no parent
+     *
+     * @internal
      */
     public function getParent(array $context)
     {
@@ -111,6 +113,8 @@ public function isTraitable()
      * @param string $name    The block name to display from the parent
      * @param array  $context The context
      * @param array  $blocks  The current set of blocks
+     *
+     * @internal
      */
     public function displayParentBlock($name, array $context, array $blocks = array())
     {
@@ -135,6 +139,8 @@ public function displayParentBlock($name, array $context, array $blocks = array(
      * @param array  $context   The context
      * @param array  $blocks    The current set of blocks
      * @param bool   $useBlocks Whether to use the current set of blocks
+     *
+     * @internal
      */
     public function displayBlock($name, array $context, array $blocks = array(), $useBlocks = true)
     {
@@ -191,6 +197,8 @@ public function displayBlock($name, array $context, array $blocks = array(), $us
      * @param array  $blocks  The current set of blocks
      *
      * @return string The rendered block
+     *
+     * @internal
      */
     public function renderParentBlock($name, array $context, array $blocks = array())
     {
@@ -212,6 +220,8 @@ public function renderParentBlock($name, array $context, array $blocks = array()
      * @param bool   $useBlocks Whether to use the current set of blocks
      *
      * @return string The rendered block
+     *
+     * @internal
      */
     public function renderBlock($name, array $context, array $blocks = array(), $useBlocks = true)
     {
@@ -237,6 +247,8 @@ public function renderBlock($name, array $context, array $blocks = array(), $use
      * @param string $name The block name
      *
      * @return bool true if the block exists, false otherwise
+     *
+     * @internal
      */
     public function hasBlock($name)
     {
@@ -252,6 +264,8 @@ public function hasBlock($name)
      * @return array An array of block names
      *
      * @see hasBlock
+     *
+     * @internal
      */
     public function getBlockNames()
     {
@@ -298,6 +312,8 @@ protected function loadTemplate($template, $templateName = null, $line = null, $
      * @return array An array of blocks
      *
      * @see hasBlock
+     *
+     * @internal
      */
     public function getBlocks()
     {
@@ -407,6 +423,8 @@ protected function displayWithErrorHandling(array $context, array $blocks = arra
      * @return mixed The content of the context variable
      *
      * @throws Twig_Error_Runtime if the variable does not exist and Twig is running in strict mode
+     *
+     * @internal
      */
     final protected function getContext($context, $item, $ignoreStrictCheck = false)
     {