diff --git a/Config.php b/Config.php
index 2125b052f16fcbc49237470cd4bae84304649d0b..d2d35e3cd61df841789ccc8ef414a6e1d32e3b8f 100644
--- a/Config.php
+++ b/Config.php
@@ -14,6 +14,9 @@ use Twig_Loader_Array;
  */
 final class Config {
 
+  /**
+   * @var array
+   */
   private static $values;
 
   /**
diff --git a/composer.json b/composer.json
index 3b4ab1c800ee388daaa23362e9a0b8dd87b4b200..b8092e0aaf4d4458d0f530e5078747004327c49b 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
         "ext-json": "*",
         "symfony/dotenv": "^3.4||^4.4||^5.0",
         "symfony/yaml": "^3.4||^4.4||^5.0",
-        "twig/twig": "^1.44"
+        "twig/twig": "^1.44||^2.12"
     },
     "require-dev": {
         "composer/composer": "^1||^2",