diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
index 202150e..6240c2b 100644
--- a/src/DependencyInjection/Configuration.php
+++ b/src/DependencyInjection/Configuration.php
@@ -17,8 +17,14 @@ class Configuration implements ConfigurationInterface
      */
     public function getConfigTreeBuilder()
     {
-        $treeBuilder = new TreeBuilder();
-        $rootNode = $treeBuilder->root('m6web_cassandra');
+        $treeBuilder = new TreeBuilder('m6web_cassandra');
+
+        if (method_exists($treeBuilder, 'getRootNode')) {
+            $rootNode = $treeBuilder->getRootNode();
+        } else {
+            // BC layer for symfony/config 4.1 and older
+            $rootNode = $treeBuilder->root('m6web_cassandra');
+        }
 
         $rootNode
             ->children()
diff --git a/src/Resources/views/Collector/cassandra.html.twig b/src/Resources/views/Collector/cassandra.html.twig
index fd915d3..cf99265 100644
--- a/src/Resources/views/Collector/cassandra.html.twig
+++ b/src/Resources/views/Collector/cassandra.html.twig
@@ -16,9 +16,7 @@
 
 {% block menu %}
     <span class="label">
-    <span class="icon">{% spaceless %}
-    <img alt="Cassandra" src="data:image/png;base64,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" />
-        {% endspaceless %}</span>
+    <span class="icon"><img alt="Cassandra" src="data:image/png;base64,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"/></span>
     <strong>Cassandra</strong>
     <span class="count">
         <span>{{ collector.commands|length }}</span>