<?php

namespace AshleyDawson\GlideBundle\DependencyInjection;

use Symfony\Component\Config\Definition\ConfigurationInterface;
use Symfony\Component\Config\Definition\Builder\TreeBuilder;

/**
 * Class Configuration
 *
 * @package AshleyDawson\GlideBundle\DependencyInjection
 */
class Configuration implements ConfigurationInterface
{
    /**
     * {@inheritdoc}
     */
    public function getConfigTreeBuilder()
    {
        $treeBuilder = new TreeBuilder('ashley_dawson_glide');

        $rootNode = $treeBuilder->getRootNode();

        $rootNode
            ->children()
                ->integerNode('max_image_size')->defaultValue(4000000)->end()
                ->scalarNode('image_manager_driver')->defaultValue('gd')->end()
            ->end()
        ;

        return $treeBuilder;
    }
}

<?php

namespace AshleyDawson\GlideBundle\DependencyInjection;

use Symfony\Component\Config\Definition\ConfigurationInterface;
use Symfony\Component\Config\Definition\Builder\TreeBuilder;

/**
 * Class Configuration
 *
 * @package AshleyDawson\GlideBundle\DependencyInjection
 */
class Configuration implements ConfigurationInterface
{
    /**
     * {@inheritdoc}
     */
    public function getConfigTreeBuilder()
    {
        $treeBuilder = new TreeBuilder();

        $rootNode = $treeBuilder->root('ashley_dawson_glide');

        $rootNode
            ->children()
                ->integerNode('max_image_size')->defaultValue(4000000)->end()
                ->scalarNode('image_manager_driver')->defaultValue('gd')->end()
            ->end()
        ;

        return $treeBuilder;
    }
}
--- 
+++ 
@@ -17,9 +17,9 @@
      */
     public function getConfigTreeBuilder()
     {
-        $treeBuilder = new TreeBuilder();
+        $treeBuilder = new TreeBuilder('ashley_dawson_glide');
 
-        $rootNode = $treeBuilder->root('ashley_dawson_glide');
+        $rootNode = $treeBuilder->getRootNode();
 
         $rootNode
             ->children()
Update TreeBuilder instantiation - fixing 4.3 deprecation
