diff --git a/.travis.yml b/.travis.yml
index 71e3bf0..9fe794e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,13 +6,14 @@ php:
   - 7.4
 
 env:
-  - SYMFONY_VERSION="2.1"
-  - SYMFONY_VERSION="3.0"
+  - SYMFONY_VERSION="3.4"
+  - SYMFONY_VERSION="4.0"
+  - SYMFONY_VERSION="4.4"
 
 before_script:
   - composer self-update
   - composer --version
   - composer require symfony/framework-bundle:${SYMFONY_VERSION} --no-update
-  - composer install -n --dev --prefer-source
+  - composer install -n --prefer-source
 
 script: phpunit --coverage-text --configuration phpunit.xml.dist
diff --git a/Controller/ElasticsearchProxyController.php b/Controller/ElasticsearchProxyController.php
index c82232c..b6e7edf 100644
--- a/Controller/ElasticsearchProxyController.php
+++ b/Controller/ElasticsearchProxyController.php
@@ -1,19 +1,19 @@
 <?php
 namespace Xola\ElasticsearchProxyBundle\Controller;
 
-use Symfony\Bundle\FrameworkBundle\Controller\Controller;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
 use Xola\ElasticsearchProxyBundle\Event\ElasticsearchProxyEvent;
 
-class ElasticsearchProxyController extends Controller
+class ElasticsearchProxyController extends AbstractController
 {
-
-    public function proxyAction(Request $request, $index, $slug)
+    public function proxyAction(Request $request, $index, $slug, ContainerInterface $container): ?Response
     {
         // Check if requested elastic search index is allowed for querying
-        $config = $this->container->getParameter('xola_elasticsearch_proxy');
+        $config = $container->getParameter('xola_elasticsearch_proxy');
         if (!in_array($index, $config['client']['indexes'])) {
             throw new AccessDeniedHttpException();
         }
@@ -31,7 +31,7 @@ public function proxyAction(Request $request, $index, $slug)
         $dispatcher->dispatch('elasticsearch_proxy.before_elasticsearch_request', $event);
         $data = $event->getQuery();
         // Get url for elastic search
-        $url = $this->getElasticSearchUrl($request->getQueryString(), $index, $slug);
+        $url = $this->getElasticSearchUrl($request->getQueryString(), $index, $slug, $container);
         $response = $this->makeRequestToElasticsearch($url, $request->getMethod(), $data);
         $event->setResponse($response);
         $dispatcher->dispatch('elasticsearch_proxy.after_elasticsearch_response', $event);
@@ -48,9 +48,9 @@ public function proxyAction(Request $request, $index, $slug)
      *
      * @return string
      */
-    public function getElasticSearchUrl($queryStr, $index, $slug)
+    public function getElasticSearchUrl($queryStr, $index, $slug, ContainerInterface $container): string
     {
-        $config = $this->container->getParameter('xola_elasticsearch_proxy');
+        $config = $container->getParameter('xola_elasticsearch_proxy');
 
         // Construct url for making elastic search request
         $url = $config['client']['protocol'] . '://' . $config['client']['host'] . ':' . $config['client']['port'] . '/' . $index . '/' . $slug;
@@ -72,7 +72,7 @@ public function getElasticSearchUrl($queryStr, $index, $slug)
      *
      * @return Response
      */
-    public function makeRequestToElasticsearch($url, $method, $data)
+    public function makeRequestToElasticsearch($url, $method, $data): Response
     {
         $ch = curl_init();
 
diff --git a/DependencyInjection/Configuration.php b/DependencyInjection/Configuration.php
index cf0501f..579403c 100644
--- a/DependencyInjection/Configuration.php
+++ b/DependencyInjection/Configuration.php
@@ -6,7 +6,7 @@
 
 class Configuration implements ConfigurationInterface
 {
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder();
         $rootNode = $treeBuilder->root('xola_elasticsearch_proxy');
@@ -26,6 +26,7 @@ public function getConfigTreeBuilder()
                 ->arrayNode('roles_skip_auth_filter')->prototype('scalar')->end()
             ->end()
         ->end();
+
         return $treeBuilder;
     }
-}
\ No newline at end of file
+}
diff --git a/DependencyInjection/XolaElasticsearchProxyExtension.php b/DependencyInjection/XolaElasticsearchProxyExtension.php
index d73d35d..77d5970 100644
--- a/DependencyInjection/XolaElasticsearchProxyExtension.php
+++ b/DependencyInjection/XolaElasticsearchProxyExtension.php
@@ -11,18 +11,10 @@ class XolaElasticsearchProxyExtension extends Extension
     public function load(array $configs, ContainerBuilder $container)
     {
         $loader = new YamlFileLoader($container, new FileLocator(__DIR__ . '/../Resources/config'));
-        $loader->load('config.yml');
-
-        $defaultConfig = $container->getParameter($this->getAlias());
-        array_splice($configs, 0, 0, array($defaultConfig));
+        $loader->load('services.yml');
 
         $configuration = new Configuration();
         $config = $this->processConfiguration($configuration, $configs);
         $container->setParameter($this->getAlias(), $config);
     }
-
-    public function getAlias()
-    {
-        return 'xola_elasticsearch_proxy';
-    }
 }
diff --git a/Event/ElasticsearchProxyEvent.php b/Event/ElasticsearchProxyEvent.php
index 0193a2e..3ba901a 100644
--- a/Event/ElasticsearchProxyEvent.php
+++ b/Event/ElasticsearchProxyEvent.php
@@ -1,12 +1,13 @@
 <?php
 
 namespace Xola\ElasticsearchProxyBundle\Event;
-use Symfony\Component\EventDispatcher\Event as SymfonyEvent;
+
+use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 
-class ElasticsearchProxyEvent extends SymfonyEvent {
-
+class ElasticsearchProxyEvent extends Event
+{
     // The request object
     protected $request;
 
@@ -30,49 +31,31 @@ public function __construct(Request $request, $index, $slug, array &$query, Resp
         $this->response = $response;
     }
 
-    /**
-     * @param mixed $request
-     */
     public function setRequest($request)
     {
         $this->request = $request;
     }
 
-    /**
-     * @return mixed
-     */
     public function getRequest()
     {
         return $this->request;
     }
 
-    /**
-     * @param mixed $index
-     */
     public function setIndex($index)
     {
         $this->index = $index;
     }
 
-    /**
-     * @return mixed
-     */
     public function getIndex()
     {
         return $this->index;
     }
 
-    /**
-     * @param mixed $slug
-     */
     public function setSlug($slug)
     {
         $this->slug = $slug;
     }
 
-    /**
-     * @return mixed
-     */
     public function getSlug()
     {
         return $this->slug;
@@ -95,18 +78,18 @@ public function getQuery()
     }
 
     /**
-     * @param \Symfony\Component\HttpFoundation\Response $response
+     * @param Response $response
      */
-    public function setResponse($response)
+    public function setResponse(Response $response)
     {
         $this->response = $response;
     }
 
     /**
-     * @return \Symfony\Component\HttpFoundation\Response
+     * @return Response
      */
-    public function getResponse()
+    public function getResponse(): ?Response
     {
         return $this->response;
     }
-}
\ No newline at end of file
+}
diff --git a/Resources/config/config.yml b/Resources/config/config.yml
deleted file mode 100644
index 0169d91..0000000
--- a/Resources/config/config.yml
+++ /dev/null
@@ -1,9 +0,0 @@
-parameters:
-    xola_elasticsearch_proxy:
-        client:
-            protocol: http
-            host: localhost
-            port: 9200
-            indexes: []
-
-        roles_skip_auth_filter: []
\ No newline at end of file
diff --git a/Resources/config/services.yml b/Resources/config/services.yml
new file mode 100644
index 0000000..59446c5
--- /dev/null
+++ b/Resources/config/services.yml
@@ -0,0 +1,8 @@
+services:
+    _defaults:
+        autowire: true
+        public: false
+
+    Xola\ElasticsearchProxyBundle\Controller\:
+        resource: '../../Controller'
+        tags: ['controller.service_arguments']
diff --git a/Tests/Controller/ElasticSearchProxyControllerTest.php b/Tests/Controller/ElasticsearchProxyControllerTest.php
similarity index 66%
rename from Tests/Controller/ElasticSearchProxyControllerTest.php
rename to Tests/Controller/ElasticsearchProxyControllerTest.php
index 7953b00..26b13f4 100644
--- a/Tests/Controller/ElasticSearchProxyControllerTest.php
+++ b/Tests/Controller/ElasticsearchProxyControllerTest.php
@@ -8,10 +8,7 @@
 
 class ElasticsearchProxyControllerTest extends TestCase
 {
-    /** @var ElasticsearchProxyController */
-    private $controller;
-
-    protected function setUp(): void
+    public function testGetElasticSearchUrl()
     {
         $container = $this->createMock(ContainerInterface::class);
         $config = array(
@@ -23,19 +20,12 @@ protected function setUp(): void
             ),
             'roles_skip_auth_filter' => array()
         );
-        $container->expects($this->any())->method("getParameter")->with("xola_elasticsearch_proxy")
+        $container->expects($this->once())->method("getParameter")->with("xola_elasticsearch_proxy")
             ->willReturn($config);
+        $controller = new ElasticsearchProxyController();
 
-        $this->controller = new ElasticsearchProxyController();
-        $this->controller->setContainer($container);
-    }
-
-
-    public function testGetElasticSearchUrl()
-    {
-        $url = $this->controller->getElasticSearchUrl('pretty=true', 'logs', '_search');
+        $url = $controller->getElasticSearchUrl('pretty=true', 'logs', '_search', $container);
 
         $this->assertEquals('http://localhost:9200/logs/_search?pretty=true', $url, 'Should be url built from proxy');
     }
-
-}
\ No newline at end of file
+}
diff --git a/composer.json b/composer.json
index 8972427..35e5dba 100644
--- a/composer.json
+++ b/composer.json
@@ -5,19 +5,9 @@
     "keywords": ["elasticsearch", "symfony", "search", "proxy", "authorization"],
     "homepage": "https://github.com/xola/XolaElasticsearchProxyBundle",
     "license": "MIT",
-    "authors": [
-        {
-            "name": "Venkata Krishna Kotra",
-            "email": "kotrakrishna@gmail.com"
-        },
-        {
-            "name": "Anush Ramani",
-            "email": "anush@xola.com"
-        }
-    ],
     "require": {
         "php": ">=7.1",
-        "symfony/framework-bundle": ">=2.1 <4.0",
+        "symfony/framework-bundle": "^3.4|^4.0",
         "ext-curl": "*",
         "ext-json": "*"
     },
@@ -25,9 +15,11 @@
         "phpunit/phpunit": "^7"
     },
     "autoload": {
-        "psr-0": {
-            "Xola\\ElasticsearchProxyBundle": ""
-        }
-    },
-    "target-dir": "Xola/ElasticsearchProxyBundle"
+        "psr-4": {
+            "Xola\\ElasticsearchProxyBundle\\": ""
+        },
+        "exclude-from-classmap": [
+            "/Tests/"
+        ]
+    }
 }