diff --git a/composer.json b/composer.json
index a6cc9c4..40208c2 100644
--- a/composer.json
+++ b/composer.json
@@ -20,8 +20,8 @@
     },
     "require": {
         "php": ">=5.6",
-        "symfony/framework-bundle": "~2.7|~3.0|~4.0",
-        "symfony/security-bundle": "~2.7|~3.0|~4.0",
+        "symfony/framework-bundle": "~2.7|~3.0|~4.0|~5.0",
+        "symfony/security-bundle": "~2.7|~3.0|~4.0|~5.0",
         "lightsaml/symfony-bridge": "~1.3"
     },
     "require-dev": {
diff --git a/src/LightSaml/SpBundle/DependencyInjection/Configuration.php b/src/LightSaml/SpBundle/DependencyInjection/Configuration.php
index 192625b..f11dc59 100644
--- a/src/LightSaml/SpBundle/DependencyInjection/Configuration.php
+++ b/src/LightSaml/SpBundle/DependencyInjection/Configuration.php
@@ -25,8 +25,14 @@ class Configuration implements ConfigurationInterface
      */
     public function getConfigTreeBuilder()
     {
-        $treeBuilder = new TreeBuilder();
-        $root = $treeBuilder->root('light_saml_sp');
+        $treeBuilder = new TreeBuilder('light_saml_sp');
+
+        if (method_exists($treeBuilder, 'getRootNode')) {
+            $root = $treeBuilder->getRootNode();
+        } else {
+            // BC layer for symfony/config 4.1 and older
+            $root = $treeBuilder->root('light_saml_sp');
+        }
 
         $root
             ->children()