diff --git a/.travis.yml b/.travis.yml
index 4205ebf7..2413fa2b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,6 +13,7 @@ env:
   global:
     - TEST_COMMAND="composer test"
     - SYMFONY_PHPUNIT_VERSION="6.3"
+    - COMPOSER_MEMORY_LIMIT=-1
 
 matrix:
     fast_finish: true
@@ -24,11 +25,11 @@ matrix:
           # Test with lowest dependencies
         - php: 7.1
           env: COMPOSER_FLAGS="--prefer-stable --prefer-lowest" SYMFONY_DEPRECATIONS_HELPER="weak" SYMFONY_PHPUNIT_VERSION="5.7"
-        - php: 5.5
+        - php: 5.6
           env: COMPOSER_FLAGS="--prefer-stable --prefer-lowest" SYMFONY_DEPRECATIONS_HELPER="weak" SYMFONY_PHPUNIT_VERSION="5.7"
 
           # Test the latest stable release
-        - php: 5.5
+        - php: 5.6
           env: SYMFONY_PHPUNIT_VERSION="5.7"
         - php: 5.6
           env: SYMFONY_PHPUNIT_VERSION="5.7"
@@ -44,7 +45,7 @@ matrix:
         - php: 7.2
           env: DEPENDENCIES="dunglas/symfony-lock:^4"
         - php: 7.0
-          env: DEPENDENCIES="dunglas/symfony-lock:^2 twig/twig:^1.34 symfony/property-access:^2.8"
+          env: DEPENDENCIES="dunglas/symfony-lock:^2 twig/twig:^1.34,<1.39 symfony/property-access:^2.8"
 
           # Latest commit to master
         - php: 7.2
diff --git a/Controller/WebUIController.php b/Controller/WebUIController.php
index 8a197f26..26a9edfb 100644
--- a/Controller/WebUIController.php
+++ b/Controller/WebUIController.php
@@ -16,6 +16,7 @@
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
 use Symfony\Component\Intl\Intl;
+use Symfony\Component\Intl\Locales;
 use Symfony\Component\Translation\MessageCatalogue;
 use Translation\Bundle\Exception\MessageValidationException;
 use Translation\Bundle\Service\StorageService;
@@ -250,7 +251,9 @@ private function getMessageFromRequest(Request $request)
     private function getLocale2LanguageMap()
     {
         $configuredLocales = $this->getParameter('php_translation.locales');
-        $names = Intl::getLocaleBundle()->getLocaleNames('en');
+        $names = class_exists(Locales::class)
+            ? Locales::getNames('en')
+            : Intl::getLocaleBundle()->getLocaleNames('en');
         $map = [];
         foreach ($configuredLocales as $l) {
             $map[$l] = isset($names[$l]) ? $names[$l] : $l;
diff --git a/Tests/Unit/Twig/BaseTwigTestCase.php b/Tests/Unit/Twig/BaseTwigTestCase.php
index 7ef74766..25f67fa6 100644
--- a/Tests/Unit/Twig/BaseTwigTestCase.php
+++ b/Tests/Unit/Twig/BaseTwigTestCase.php
@@ -16,6 +16,7 @@
 use Symfony\Component\Translation\IdentityTranslator;
 use Symfony\Bridge\Twig\Extension\TranslationExtension as SymfonyTranslationExtension;
 use Translation\Bundle\Twig\TranslationExtension;
+use Twig\Loader\ArrayLoader;
 
 /**
  * @author Johannes M. Schmitt <schmittjoh@gmail.com>
@@ -26,10 +27,13 @@ final protected function parse($file, $debug = false)
     {
         $content = file_get_contents(__DIR__.'/Fixture/'.$file);
 
-        $env = new \Twig_Environment(new \Twig_Loader_Array([]));
+        $loader = class_exists(ArrayLoader::class)
+            ? new ArrayLoader()
+            : new \Twig_Loader_Array([]);
+        $env = new \Twig_Environment($loader);
         $env->addExtension(new SymfonyTranslationExtension($translator = new IdentityTranslator(new MessageSelector())));
         $env->addExtension(new TranslationExtension($translator, $debug));
 
-        return $env->parse($env->tokenize(new \Twig_Source($content, null)))->getNode('body');
+        return $env->parse($env->tokenize(new \Twig_Source($content, '')))->getNode('body');
     }
 }
diff --git a/composer.json b/composer.json
index 4ce9509a..d8919f10 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
         "php": "^5.5 || ^7.0",
         "symfony/framework-bundle": "^2.7 || ^3.0 || ^4.0",
         "symfony/validator": "^2.7 || ^3.0 || ^4.0",
-        "symfony/translation": "^2.7 || ^3.0 || ^4.0",
+        "symfony/translation": "^2.7 || ^3.0 || ^4.0,<4.2",
         "symfony/twig-bundle": "^2.7 || ^3.0 || ^4.0",
         "symfony/finder": "^2.7 || ^3.0 || ^4.0",
         "symfony/intl": "^2.7 || ^3.0 || ^4.0",
@@ -21,10 +21,11 @@
         "php-translation/common": "^1.0",
         "php-translation/symfony-storage": "^1.0",
         "php-translation/extractor": "^1.3",
-        "nyholm/nsa": "^1.1"
+        "nyholm/nsa": "^1.1",
+        "twig/twig": "<1.39 || ^2.0,<2.8"
     },
     "require-dev": {
-        "symfony/phpunit-bridge": "^3.4 || ^4.0",
+        "symfony/phpunit-bridge": "^3.4.19 || ^4.0",
         "php-translation/translator": "^1.0",
         "php-http/curl-client": "^1.7",
         "php-http/message": "^1.6",
@@ -35,8 +36,8 @@
         "symfony/templating": "^2.7 || ^3.0 || ^4.0",
         "symfony/dependency-injection": "^2.7 || ^3.0 || ^4.0",
         "symfony/web-profiler-bundle": "^2.7 || ^3.0 || ^4.0",
-        "matthiasnoback/symfony-dependency-injection-test": "^1.2 || ^2.3",
-        "matthiasnoback/symfony-config-test": "^2.2 || ^3.1",
+        "matthiasnoback/symfony-dependency-injection-test": "^1.2 || ^2.3 || ^3.0",
+        "matthiasnoback/symfony-config-test": "^2.2 || ^3.1 || ^4.0",
         "guzzlehttp/psr7": "^1.4",
         "nyholm/symfony-bundle-test": "^1.2.3"
     },
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 5a93c70c..baabcc35 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -15,6 +15,7 @@
 
     <php>
         <env name="ENV" value="test" />
+        <env name="SYMFONY_DEPRECATIONS_HELPER" value="verbose=1" />
     </php>
 
     <formatter type="clover" usefile="false"/>