diff --git a/core/core.services.yml b/core/core.services.yml
index 5996bb9..7cdd453 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -1047,7 +1047,7 @@ services:
     arguments: ['@twig.loader_chain', '@module_handler', '@theme_handler', '%twig.config%']
     tags:
       - { name: service_collector, tag: 'twig.extension', call: addExtension }
-      # - { name: service_collector, tag: 'twig.loader', call: addLoader }
+      - { name: service_collector, tag: 'twig.loader', call: addLoader }
   twig.extension:
     class: Drupal\Core\Template\TwigExtension
     tags:
@@ -1063,20 +1063,22 @@ services:
       - { name: twig.extension }
   twig.loader_chain:
     class: Twig_Loader_Chain
-    calls:
-      - [addLoader, [@twig.loader]]
-      - [addLoader, [@twig.loader.theme_registry]]
-      - [addLoader, [@twig.loader.string]]
   twig.loader:
     alias: twig.loader.filesystem
   twig.loader.filesystem:
     class: Twig_Loader_Filesystem
     arguments: ['%app.root%']
+    tags:
+      - { name: twig.loader, priority: 100 }
   twig.loader.theme_registry:
     class: Drupal\Core\Template\TwigThemeRegistryLoader
     arguments: ['@theme.registry']
+    tags:
+      - { name: twig.loader, priority: 0 }
   twig.loader.string:
     class: Twig_Loader_String
+    tags:
+      - { name: twig.loader, priority: -100 }
   element_info:
     alias: plugin.manager.element_info
   file.mime_type.guesser:
diff --git a/core/lib/Drupal/Core/Template/TwigEnvironment.php b/core/lib/Drupal/Core/Template/TwigEnvironment.php
index 464250c..67d461a 100644
--- a/core/lib/Drupal/Core/Template/TwigEnvironment.php
+++ b/core/lib/Drupal/Core/Template/TwigEnvironment.php
@@ -213,4 +213,16 @@ public function renderInline($template_string, array $context = array()) {
     return $this->loadTemplate($template_string, NULL)->render($context);
   }
 
+  /**
+   * Adds a new loader to the Twig environment.
+   *
+   * @param Twig_LoaderInterface $loader A Loader instance
+   */
+  public function addLoader(\Twig_LoaderInterface $loader) {
+    if ($this->extensionInitialized) {
+      throw new \LogicException('Unable to add a loader as extensions have already been initialized.');
+    }
+    $this->loader->addLoader($loader);
+  }
+
 }