diff --git a/.scrutinizer.yml b/.scrutinizer.yml
index 99bd6605c..37ffbfe2e 100644
--- a/.scrutinizer.yml
+++ b/.scrutinizer.yml
@@ -1,7 +1,7 @@
 tools:
     external_code_coverage:
         timeout: 2000
-        runs: 2
+        runs: 12
 
 filter:
     excluded_paths:
diff --git a/.travis.yml b/.travis.yml
index b5fe1d9c1..eca9ff414 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,6 +30,7 @@ after_script:
     - php ocular.phar code-coverage:upload --format=php-clover var/phpunit/logs/clover.xml
 
 env:
+    - SYMFONY_VERSION=3.4.*
     - SYMFONY_VERSION=4.4.*
     - SYMFONY_VERSION=5.0.*
     - SYMFONY_VERSION=5.1.*
diff --git a/src/Configuration/ActionConfiguration.php b/src/Configuration/ActionConfiguration.php
index 88803d41a..384596bde 100644
--- a/src/Configuration/ActionConfiguration.php
+++ b/src/Configuration/ActionConfiguration.php
@@ -363,22 +363,6 @@ protected function configureMenu(OptionsResolver $resolver): void
                     $value = [];
                 }
 
-//                foreach ($value as $menuName => $menuConfiguration) {
-//                    if (count($value) !== 0) {
-//                        return $value;
-//                    }
-//
-//                    if ($menuName === 'top') {
-//                        if ($this->actionName === 'create') {
-//                            if (empty($menuConfiguration['children']) || count($menuConfiguration['children']) === 0) {
-//                                $value[$menuName]['children'] = [
-//                                    'create' => null,
-//                                ];
-//                            }
-//                        }
-//                    }
-//                }
-
                 return $value;
             })
         ;
diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
index f168c5484..72e447a80 100644
--- a/src/DependencyInjection/Configuration.php
+++ b/src/DependencyInjection/Configuration.php
@@ -16,7 +16,12 @@ class Configuration implements ConfigurationInterface
     public function getConfigTreeBuilder()
     {
         $treeBuilder = new TreeBuilder('lag_admin');
-        $rootNode = $treeBuilder->getRootNode();
+
+        if (method_exists(TreeBuilder::class, 'getRootNode')) {
+            $rootNode = $treeBuilder->getRootNode();
+        } else {
+            $rootNode = $treeBuilder->root('lag_admin');
+        }
 
         $rootNode
             ->children()
@@ -32,13 +37,28 @@ public function getConfigTreeBuilder()
         return $treeBuilder;
     }
 
+    /**
+     * This method preserves the compatibility with Symfony 3.4.
+     */
+    protected function createRootNode(string $name): NodeDefinition
+    {
+        if (method_exists(TreeBuilder::class, 'getRootNode')) {
+            $treeBuilder = new TreeBuilder($name);
+
+            return $treeBuilder->getRootNode();
+        } else {
+            $treeBuilder = new TreeBuilder();
+
+            return $treeBuilder->root($name);
+        }
+    }
+
     /**
      * @return ArrayNodeDefinition|NodeDefinition
      */
     protected function getAdminsConfigurationNode()
     {
-        $builder = new TreeBuilder('admins');
-        $node = $builder->getRootNode();
+        $node = $this->createRootNode('admins');
 
         $node
             // useAttributeAsKey() method will preserve keys when multiple configurations files are used and then avoid
@@ -64,8 +84,7 @@ protected function getAdminsConfigurationNode()
      */
     protected function getApplicationNode()
     {
-        $builder = new TreeBuilder('application');
-        $node = $builder->getRootNode();
+        $node = $this->createRootNode('application');
 
         $node
             ->children()
@@ -123,8 +142,7 @@ protected function getApplicationNode()
      */
     protected function getMenuConfiguration()
     {
-        $builder = new TreeBuilder('menus');
-        $node = $builder->getRootNode();
+        $node = $this->createRootNode('menus');
 
         $node
             ->prototype('variable')