diff --git a/composer.json b/composer.json
index 0bbbd4d..0b0354a 100644
--- a/composer.json
+++ b/composer.json
@@ -12,17 +12,17 @@
     ],
     "require": {
         "php": ">=5.3.9",
-        "phpmentors/workflower": "~1.2",
-        "symfony/config": "~2.8 || ~3.0 || ~4.0",
-        "symfony/dependency-injection": "~2.8 || ~3.0 || ~4.0",
-        "symfony/finder": "~2.8 || ~3.0 || ~4.0",
-        "symfony/http-kernel": "~2.8 || ~3.0 || ~4.0",
-        "symfony/security-core": "~2.8 || ~3.0 || ~4.0",
-        "symfony/security-bundle": "~2.8 || ~3.0 || ~4.0"
+        "phpmentors/workflower": "dev-symfony5",
+        "symfony/config": "~4.0 || ~5.0",
+        "symfony/dependency-injection": "~4.0 || ~5.0",
+        "symfony/finder": "~4.0 || ~5.0",
+        "symfony/http-kernel": "~4.0 || ~5.0",
+        "symfony/security-core": "~4.0 || ~5.0",
+        "symfony/security-bundle": "~4.0 || ~5.0"
     },
     "require-dev": {
         "doctrine/orm": "~2.4",
-        "symfony/doctrine-bridge": "~2.8 || ~3.0 || ~4.0"
+        "symfony/doctrine-bridge": "~4.0 || ~5.0"
     },
     "suggest": {
         "doctrine/orm": ">= 2.4.0 provides transparent serialization/deserialization support for entities with Doctrine ORM",
diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
index 8d0e248..0685678 100644
--- a/src/DependencyInjection/Configuration.php
+++ b/src/DependencyInjection/Configuration.php
@@ -22,8 +22,8 @@ class Configuration implements ConfigurationInterface
      */
     public function getConfigTreeBuilder()
     {
-        $treeBuilder = new TreeBuilder();
-        $treeBuilder->root('phpmentors_workflower')
+        $treeBuilder = new TreeBuilder('phpmentors_workflower');
+        $treeBuilder->getRootNode()
             ->children()
                 ->scalarNode('serializer_service')
                     ->defaultValue('phpmentors_workflower.php_workflow_serializer')