diff --git a/Controller/CaptchaController.php b/Controller/CaptchaController.php
index 8d8d83e..d3c5751 100644
--- a/Controller/CaptchaController.php
+++ b/Controller/CaptchaController.php
@@ -1,32 +1,37 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Gregwar\CaptchaBundle\Controller;
 
+use Gregwar\CaptchaBundle\Generator\CaptchaGenerator;
 use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
 /**
- * Generates a captcha via a URL
+ * Generates a captcha via a URL.
  *
  * @author Jeremy Livingston <jeremy.j.livingston@gmail.com>
  */
 class CaptchaController extends AbstractController
 {
-    /**
-     * Action that is used to generate the captcha, save its code, and stream the image
-     *
-     * @param string $key
-     *
-     * @return Response
-     *
-     * @throws NotFoundHttpException
-     */
-    public function generateCaptchaAction($key)
+    /** @var CaptchaGenerator */
+    private $captchaGenerator;
+
+    /** @var array */
+    private $config;
+
+    public function __construct(CaptchaGenerator $captchaGenerator, array $config)
     {
-        $options = $this->container->getParameter('gregwar_captcha.config');
-        $session = $this->get('session');
-        $whitelistKey = $options['whitelist_key'];
+        $this->captchaGenerator = $captchaGenerator;
+        $this->config = $config;
+    }
+
+    public function generateCaptchaAction(Request $request, string $key): Response
+    {
+        $session = $request->getSession();
+        $whitelistKey = $this->config['whitelist_key'];
         $isOk = false;
 
         if ($session->has($whitelistKey)) {
@@ -37,21 +42,18 @@ class CaptchaController extends AbstractController
         }
 
         if (!$isOk) {
-            return $this->error($options);
+            return $this->error($this->config);
         }
 
-        /* @var \Gregwar\CaptchaBundle\Generator\CaptchaGenerator $generator */
-        $generator = $this->container->get('gregwar_captcha.generator');
-
         $persistedOptions = $session->get($key, array());
-        $options = array_merge($options, $persistedOptions);
+        $options = array_merge($this->config, $persistedOptions);
 
-        $phrase = $generator->getPhrase($options);
-        $generator->setPhrase($phrase);
+        $phrase = $this->captchaGenerator->getPhrase($options);
+        $this->captchaGenerator->setPhrase($phrase);
         $persistedOptions['phrase'] = $phrase;
         $session->set($key, $persistedOptions);
 
-        $response = new Response($generator->generate($options));
+        $response = new Response($this->captchaGenerator->generate($options));
         $response->headers->set('Content-type', 'image/jpeg');
         $response->headers->set('Pragma', 'no-cache');
         $response->headers->set('Cache-Control', 'no-cache');
@@ -59,20 +61,11 @@ class CaptchaController extends AbstractController
         return $response;
     }
 
-    /**
-     * Returns an empty image with status code 428 Precondition Required
-     *
-     * @param array $options
-     *
-     * @return Response
-     */
-    protected function error($options)
+    private function error(array $options): Response
     {
-        /* @var \Gregwar\CaptchaBundle\Generator\CaptchaGenerator $generator */
-        $generator = $this->container->get('gregwar_captcha.generator');
-        $generator->setPhrase('');
+        $this->captchaGenerator->setPhrase('');
 
-        $response = new Response($generator->generate($options));
+        $response = new Response($this->captchaGenerator->generate($options));
         $response->setStatusCode(428);
         $response->headers->set('Content-type', 'image/jpeg');
         $response->headers->set('Pragma', 'no-cache');
diff --git a/DependencyInjection/Configuration.php b/DependencyInjection/Configuration.php
index 3683c20..ab4b23c 100644
--- a/DependencyInjection/Configuration.php
+++ b/DependencyInjection/Configuration.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Gregwar\CaptchaBundle\DependencyInjection;
 
 use Symfony\Component\Config\Definition\Builder\TreeBuilder;
@@ -7,21 +9,10 @@ use Symfony\Component\Config\Definition\ConfigurationInterface;
 
 class Configuration implements ConfigurationInterface
 {
-    /**
-     * Generates the configuration tree.
-     *
-     * @return TreeBuilder
-     */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder('gregwar_captcha');
-
-        if (method_exists($treeBuilder, 'getRootNode')) {
-            $rootNode = $treeBuilder->getRootNode();
-        } else {
-            // BC for symfony/config <= 4.1
-            $rootNode = $treeBuilder->root('gregwar_captcha');
-        }
+        $rootNode = $treeBuilder->getRootNode();
 
         $rootNode
             ->addDefaultsIfNotSet()
@@ -36,7 +27,7 @@ class Configuration implements ConfigurationInterface
                 ->scalarNode('as_url')->defaultValue(false)->end()
                 ->scalarNode('reload')->defaultValue(false)->end()
                 ->scalarNode('image_folder')->defaultValue('captcha')->end()
-                ->scalarNode('web_path')->defaultValue('%kernel.root_dir%/../web')->end()
+                ->scalarNode('web_path')->defaultValue('%kernel.project_dir%/public')->end()
                 ->scalarNode('gc_freq')->defaultValue(100)->end()
                 ->scalarNode('expiration')->defaultValue(60)->end()
                 ->scalarNode('quality')->defaultValue(50)->end()
diff --git a/DependencyInjection/GregwarCaptchaExtension.php b/DependencyInjection/GregwarCaptchaExtension.php
index 740b3e6..060fff8 100755
--- a/DependencyInjection/GregwarCaptchaExtension.php
+++ b/DependencyInjection/GregwarCaptchaExtension.php
@@ -1,24 +1,29 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Gregwar\CaptchaBundle\DependencyInjection;
 
+use Exception;
 use Symfony\Component\HttpKernel\DependencyInjection\Extension;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
 use Symfony\Component\Config\FileLocator;
 
 /**
- * Extension used to load the configuration, set parameters, and initialize the captcha view
+ * Extension used to load the configuration, set parameters, and initialize the captcha view.
  *
  * @author Gregwar <g.passault@gmail.com>
  */
 class GregwarCaptchaExtension extends Extension
 {
     /**
-     * @param array $configs
+     * @param array            $configs
      * @param ContainerBuilder $container
+     *
+     * @throws Exception
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $loader = new YamlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
         $loader->load('services.yml');
diff --git a/Generator/CaptchaGenerator.php b/Generator/CaptchaGenerator.php
index 58ff58a..08b33dc 100644
--- a/Generator/CaptchaGenerator.php
+++ b/Generator/CaptchaGenerator.php
@@ -1,48 +1,40 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Gregwar\CaptchaBundle\Generator;
 
 use Gregwar\Captcha\CaptchaBuilder;
 use Gregwar\Captcha\PhraseBuilder;
-use Symfony\Component\HttpFoundation\Session\SessionInterface;
 use Symfony\Component\Routing\RouterInterface;
-
 use Gregwar\Captcha\CaptchaBuilderInterface;
 use Gregwar\Captcha\PhraseBuilderInterface;
 
 /**
- * Uses configuration parameters to call the services that generate captcha images
+ * Uses configuration parameters to call the services that generate captcha images.
  *
  * @author Gregwar <g.passault@gmail.com>
  * @author Jeremy Livingston <jeremy.j.livingston@gmail.com>
  */
 class CaptchaGenerator
 {
-    /**
-     * @var RouterInterface
-     */
+    /** @var RouterInterface */
     protected $router;
 
-    /**
-     * @var CaptchaBuilder
-     */
+    /** @var CaptchaBuilder */
     protected $builder;
 
-    /**
-     * @var PhraseBuilder
-     */
+    /** @var PhraseBuilder */
     protected $phraseBuilder;
 
-    /**
-     * @var ImageFileHandler
-     */
+    /** @var ImageFileHandler */
     protected $imageFileHandler;
 
     /**
-     * @param RouterInterface $router
+     * @param RouterInterface         $router
      * @param CaptchaBuilderInterface $builder
-     * @param PhraseBuilderInterface $phraseBuilder
-     * @param ImageFileHandler $imageFileHandler
+     * @param PhraseBuilderInterface  $phraseBuilder
+     * @param ImageFileHandler        $imageFileHandler
      */
     public function __construct(
         RouterInterface $router,
@@ -50,20 +42,13 @@ class CaptchaGenerator
         PhraseBuilderInterface $phraseBuilder,
         ImageFileHandler $imageFileHandler
     ) {
-        $this->router           = $router;
-        $this->builder          = $builder;
-        $this->phraseBuilder    = $phraseBuilder;
-        $this->imageFileHandler = $imageFileHandler;    
+        $this->router = $router;
+        $this->builder = $builder;
+        $this->phraseBuilder = $phraseBuilder;
+        $this->imageFileHandler = $imageFileHandler;
     }
 
-    /**
-     * Get the captcha URL, stream, or filename that will go in the image's src attribute
-     *
-     * @param array $options
-     *
-     * @return array
-     */
-    public function getCaptchaCode(array &$options)
+    public function getCaptchaCode(array &$options): string
     {
         $this->builder->setPhrase($this->getPhrase($options));
 
@@ -76,27 +61,21 @@ class CaptchaGenerator
 
         // Returns the image generation URL
         if ($options['as_url']) {
-            return $this->router->generate('gregwar_captcha.generate_captcha', 
-                array('key' => $options['session_key'], 'n' => md5(microtime(true).mt_rand())));
+            return $this->router->generate(
+                'gregwar_captcha.generate_captcha',
+                array('key' => $options['session_key'], 'n' => md5(microtime(true).mt_rand()))
+            );
         }
 
-        return 'data:image/jpeg;base64,' . base64_encode($this->generate($options));
+        return 'data:image/jpeg;base64,'.base64_encode($this->generate($options));
     }
 
-    /**
-     * Sets the phrase to the builder
-     */
-    public function setPhrase($phrase)
+    public function setPhrase(string $phrase): void
     {
         $this->builder->setPhrase($phrase);
     }
 
-    /**
-     * @param array $options
-     *
-     * @return string
-     */
-    public function generate(array &$options)
+    public function generate(array &$options): string
     {
         $this->builder->setDistortion($options['distortion']);
 
@@ -104,7 +83,7 @@ class CaptchaGenerator
         $this->builder->setMaxBehindLines($options['max_behind_lines']);
 
         if (isset($options['text_color']) && $options['text_color']) {
-            if (count($options['text_color']) !== 3) {
+            if (3 !== count($options['text_color'])) {
                 throw new \RuntimeException('text_color should be an array of r, g and b');
             }
 
@@ -113,7 +92,7 @@ class CaptchaGenerator
         }
 
         if (isset($options['background_color']) && $options['background_color']) {
-            if (count($options['background_color']) !== 3) {
+            if (3 !== count($options['background_color'])) {
                 throw new \RuntimeException('background_color should be an array of r, g and b');
             }
 
@@ -149,12 +128,7 @@ class CaptchaGenerator
         return $this->imageFileHandler->saveAsFile($content);
     }
 
-    /**
-     * @param array $options
-     *
-     * @return string
-     */
-    public function getPhrase(array &$options)
+    public function getPhrase(array &$options): string
     {
         // Get the phrase that we'll use for this image
         if ($options['keep_value'] && isset($options['phrase'])) {
@@ -163,7 +137,7 @@ class CaptchaGenerator
             $phrase = $this->phraseBuilder->build($options['length'], $options['charset']);
             $options['phrase'] = $phrase;
         }
-        
+
         return $phrase;
     }
 }
diff --git a/Generator/ImageFileHandler.php b/Generator/ImageFileHandler.php
index 71dda0f..616d6f2 100644
--- a/Generator/ImageFileHandler.php
+++ b/Generator/ImageFileHandler.php
@@ -1,11 +1,13 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Gregwar\CaptchaBundle\Generator;
 
 use Symfony\Component\Finder\Finder;
 
 /**
- * Handles actions related to captcha image files including saving and garbage collection
+ * Handles actions related to captcha image files including saving and garbage collection.
  *
  * @author Gregwar <g.passault@gmail.com>
  * @author Jeremy Livingston <jeremy@quizzle.com>
@@ -13,69 +15,61 @@ use Symfony\Component\Finder\Finder;
 class ImageFileHandler
 {
     /**
-     * Name of folder for captcha images
+     * Name of folder for captcha images.
+     *
      * @var string
      */
     protected $imageFolder;
 
     /**
-     * Absolute path to public web folder
+     * Absolute path to public web folder.
+     *
      * @var string
      */
     protected $webPath;
 
     /**
-     * Frequency of garbage collection in fractions of 1
+     * Frequency of garbage collection in fractions of 1.
+     *
      * @var int
      */
     protected $gcFreq;
 
     /**
-     * Maximum age of images in minutes
+     * Maximum age of images in minutes.
+     *
      * @var int
      */
     protected $expiration;
 
     /**
-     * @param $imageFolder
-     * @param $webPath
-     * @param $gcFreq
-     * @param $expiration
+     * @param string $imageFolder
+     * @param string $webPath
+     * @param string $gcFreq
+     * @param string $expiration
      */
-    public function __construct($imageFolder, $webPath, $gcFreq, $expiration)
+    public function __construct(string $imageFolder, string $webPath, string $gcFreq, string $expiration)
     {
-        $this->imageFolder      = $imageFolder;
-        $this->webPath          = $webPath;
-        $this->gcFreq           = $gcFreq;
-        $this->expiration       = $expiration;
+        $this->imageFolder = $imageFolder;
+        $this->webPath = $webPath;
+        $this->gcFreq = $gcFreq;
+        $this->expiration = $expiration;
     }
 
-    /**
-     * Saves the provided image content as a file
-     *
-     * @param string $contents
-     *
-     * @return string
-     */
-    public function saveAsFile($contents)
+    public function saveAsFile($contents): string
     {
         $this->createFolderIfMissing();
 
-        $filename = md5(uniqid()) . '.jpg';
-        $filePath = $this->webPath . '/' . $this->imageFolder . '/' . $filename;
+        $filename = md5(uniqid()).'.jpg';
+        $filePath = $this->webPath.'/'.$this->imageFolder.'/'.$filename;
         imagejpeg($contents, $filePath, 15);
 
-        return '/' . $this->imageFolder . '/' . $filename;
+        return '/'.$this->imageFolder.'/'.$filename;
     }
 
-    /**
-     * Randomly runs garbage collection on the image directory
-     *
-     * @return bool
-     */
-    public function collectGarbage()
+    public function collectGarbage(): bool
     {
-        if (!mt_rand(1, $this->gcFreq) == 1) {
+        if (1 == !mt_rand(1, $this->gcFreq)) {
             return false;
         }
 
@@ -83,23 +77,20 @@ class ImageFileHandler
 
         $finder = new Finder();
         $criteria = sprintf('<= now - %s minutes', $this->expiration);
-        $finder->in($this->webPath . '/' . $this->imageFolder)
+        $finder->in($this->webPath.'/'.$this->imageFolder)
             ->date($criteria);
 
-        foreach($finder->files() as $file) {
+        foreach ($finder->files() as $file) {
             unlink($file->getPathname());
         }
 
         return true;
     }
 
-    /**
-     * Creates the folder if it doesn't exist
-     */
-    protected function createFolderIfMissing()
+    protected function createFolderIfMissing(): void
     {
-        if (!file_exists($this->webPath . '/' . $this->imageFolder)) {
-            mkdir($this->webPath . '/' . $this->imageFolder, 0755);
+        if (!file_exists($this->webPath.'/'.$this->imageFolder)) {
+            mkdir($this->webPath.'/'.$this->imageFolder, 0755);
         }
     }
 }
diff --git a/GregwarCaptchaBundle.php b/GregwarCaptchaBundle.php
index 9ad5967..838fc20 100755
--- a/GregwarCaptchaBundle.php
+++ b/GregwarCaptchaBundle.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Gregwar\CaptchaBundle;
 
 use Symfony\Component\HttpKernel\Bundle\Bundle;
diff --git a/README.md b/README.md
index ec9397a..5cc45be 100644
--- a/README.md
+++ b/README.md
@@ -11,106 +11,45 @@ It uses [gregwar/captcha](https://github.com/Gregwar/Captcha) as captcha generat
 Compatibility with Symfony
 ==========================
 
-If you are using Symfony `< 2.8`, you should use version `1.*`
+| CaptchaBundle   | Symfony   | PHP     |
+|:---------------:|:---------:|:-------:|
+| 3.*             | 4.* - 5.* | 7.1 >   |
+| 2.*             | 2.8 - 3.* | 5.3.9 > |
+| 1.*             | 2.1 - 2.7 | 5.3.0 > |
 
-If you are using Symfony `>= 2.8`, you should use version `2.*`
 
 Installation
 ============
 
 ### Step 1: Download the GregwarCaptchaBundle
 
-Ultimately, the GregwarCaptchaBundle files should be downloaded to the
-'vendor/bundles/Gregwar/CaptchaBundle' directory.
-
-You can accomplish this several ways, depending on your personal preference.
-The first method is the standard Symfony method.
-
-***Using Composer***
-
-Use composer require to download and install the package.
+Use composer require to download and install the package. 
+At the end of the installation you can automaticly create the configuration thanks to the Symfony recipe.
 
 ``` bash
     composer require gregwar/captcha-bundle
 ```
 
-***Using the vendors script***
-
-Add the following lines to your `deps` file:
-
-```
-    [GregwarCaptchaBundle]
-        git=http://github.com/Gregwar/CaptchaBundle.git
-        target=/bundles/Gregwar/CaptchaBundle
-        version=origin/2.0 <- add this if you are using Symfony 2.0
-```
-
-Now, run the vendors script to download the bundle:
-
-``` bash
-$ php bin/vendors install
-```
-
-***Using submodules***
-
-If you prefer instead to use git submodules, then run the following:
-
-``` bash
-$ git submodule add git://github.com/Gregwar/CaptchaBundle.git vendor/bundles/Gregwar/CaptchaBundle
-$ git submodule update --init
-```
-
-### Step 2: Configure the Autoloader
-
-If you use composer, you can skip this step.
-
-Now you will need to add the `Gregwar` namespace to your autoloader:
-
-``` php
-<?php
-// app/autoload.php
-
-$loader->registerNamespaces(array(
-    // ...
-    'Gregwar' => __DIR__.'/../vendor/bundles',
-));
-```
-### Step 3: Enable the bundle
-
-Finally, enable the bundle in the kernel:
-
-```php
-<?php
-// app/appKernel.php
-
-public function registerBundles()
-{
-    $bundles = array(
-        // ...
-        new Gregwar\CaptchaBundle\GregwarCaptchaBundle(),
-    );
-}
-```
-
 Configuration
 =============
 
-Add the following configuration to your `app/config/config.yml`:
+If you made the configuration automaticly trough the Symfony recipe, you should have the following config file `/config/packages/gregwar_captcha.yaml` 
 
+Otherwise you can create it manually `/config/packages/gregwar_captcha.yaml` with the following default configuration:
+``` yaml
     gregwar_captcha: ~
+```
 
 Usage
 =====
 
 You can use the "captcha" type in your forms this way:
 
-```php
+``` php
 <?php
     use Gregwar\CaptchaBundle\Type\CaptchaType;
     // ...
     $builder->add('captcha', CaptchaType::class); // That's all !
-    // If you're using php<5.5, you can use instead:
-    $builder->add('captcha', 'Gregwar\CaptchaBundle\Type\CaptchaType');
     // ...
 ```
 
@@ -123,7 +62,7 @@ Options
 You can define the following configuration options globally:
 
 * **image_folder**: name of folder for captcha images relative to public web folder in case **as_file** is set to true (default="captcha")
-* **web_path**: absolute path to public web folder (default="%kernel.root_dir%/../web")
+* **web_path**: absolute path to public web folder (default='%kernel.project_dir%/public')
 * **gc_freq**: frequency of garbage collection in fractions of 1 (default=100)
 * **expiration**: maximum lifetime of captcha image files in minutes (default=60)
 
@@ -155,7 +94,7 @@ number of lines depends on the size of the image). (default=null)
 
 Example :
 
-```php
+``` php
 <?php
     use Gregwar\CaptchaBundle\Type\CaptchaType;
     // ...
@@ -168,11 +107,12 @@ Example :
 
 You can also set these options for your whole application using the `gregwar_captcha`
 configuration entry in your `config.yml` file:
-
+``` yaml 
     gregwar_captcha:
         width: 200
         height: 50
         length: 6
+```
 
 Translation
 ===========
@@ -182,15 +122,17 @@ The messages are using the translator, you can either change the `invalid_messag
 As URL
 ============
 To use a URL to generate a captcha image, you must add the bundle's routing configuration to your app/routing.yml file:
-
+``` yaml 
     gregwar_captcha_routing:
         resource: "@GregwarCaptchaBundle/Resources/config/routing/routing.yml"
+```
 
 This will use the bundle's route of "/generate-captcha/{key}" to handle the generation. If this route conflicts with an application route, you can prefix the bundle's routes when you import:
-
+``` yaml 
     gregwar_captcha_routing:
         resource: "@GregwarCaptchaBundle/Resources/config/routing/routing.yml"
         prefix: /_gcb
+```
 
 Since the session key is transported in the URL, it's also added in another session array, under the `whitelist_key` key, for security reasons
 
@@ -201,7 +143,7 @@ The widget support the standard Symfony theming, see the [documentation](http://
 
 The default rendering is:
 
-```html
+``` twig
 {% block captcha_widget %}
 {% spaceless %}
     <img src="{{ captcha_code }}" title="captcha" width="{{ captcha_width }}" height="{{ captcha_height }}" />
diff --git a/Resources/config/services.yml b/Resources/config/services.yml
index fca2c44..04dff56 100755
--- a/Resources/config/services.yml
+++ b/Resources/config/services.yml
@@ -1,4 +1,5 @@
 parameters:
+    gregwar_captcha.controller.class: Gregwar\CaptchaBundle\Controller\CaptchaController
     gregwar_captcha.captcha_type.class: Gregwar\CaptchaBundle\Type\CaptchaType
     gregwar_captcha.captcha_generator.class: Gregwar\CaptchaBundle\Generator\CaptchaGenerator
     gregwar_captcha.image_file_handler.class: Gregwar\CaptchaBundle\Generator\ImageFileHandler
@@ -6,7 +7,15 @@ parameters:
     gregwar_captcha.phrase_builder.class: Gregwar\Captcha\PhraseBuilder
     
 services:
-    captcha.type:
+    gregwar_captcha.controller:
+        class: '%gregwar_captcha.controller.class%'
+        public: true
+        arguments:
+            - '@gregwar_captcha.generator'
+            - '%gregwar_captcha.config%'
+
+#    captcha.type:
+    gregwar_captcha.type:
         class: '%gregwar_captcha.captcha_type.class%'
         public: true
         arguments:
diff --git a/Type/CaptchaType.php b/Type/CaptchaType.php
index ac9d00a..8e659ea 100644
--- a/Type/CaptchaType.php
+++ b/Type/CaptchaType.php
@@ -1,22 +1,23 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Gregwar\CaptchaBundle\Type;
 
+use Symfony\Component\Form\Extension\Core\Type\TextType;
 use Symfony\Component\HttpFoundation\Session\SessionInterface;
 use Symfony\Component\Form\FormView;
 use Symfony\Component\Form\FormInterface;
 use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\OptionsResolver\OptionsResolver;
-use Symfony\Component\OptionsResolver\OptionsResolverInterface;
 use Symfony\Component\Form\FormEvents;
-use Symfony\Component\Translation\TranslatorInterface;
-
+use Symfony\Contracts\Translation\TranslatorInterface;
 use Gregwar\CaptchaBundle\Validator\CaptchaValidator;
 use Gregwar\CaptchaBundle\Generator\CaptchaGenerator;
 
 /**
- * Captcha type
+ * Captcha type.
  *
  * @author Gregwar <g.passault@gmail.com>
  */
@@ -24,25 +25,16 @@ class CaptchaType extends AbstractType
 {
     const SESSION_KEY_PREFIX = '_captcha_';
 
-    /**
-     * @var SessionInterface
-     */
+    /** @var SessionInterface */
     protected $session;
 
-    /**
-     * @var CaptchaGenerator
-     */
+    /** @var CaptchaGenerator */
     protected $generator;
 
-    /**
-     * @var TranslatorInterface
-     */
+    /** @var TranslatorInterface */
     protected $translator;
 
-    /**
-     * Options
-     * @var array
-     */
+    /** @var array */
     private $options = array();
 
     /**
@@ -53,10 +45,10 @@ class CaptchaType extends AbstractType
      */
     public function __construct(SessionInterface $session, CaptchaGenerator $generator, TranslatorInterface $translator, $options)
     {
-        $this->session      = $session;
-        $this->generator    = $generator;
-        $this->translator   = $translator;
-        $this->options      = $options;
+        $this->session = $session;
+        $this->generator = $generator;
+        $this->translator = $translator;
+        $this->options = $options;
     }
 
     /**
@@ -72,8 +64,8 @@ class CaptchaType extends AbstractType
             $options['bypass_code'],
             $options['humanity']
         );
-        $event = \Symfony\Component\HttpKernel\Kernel::VERSION >= 2.3 ? FormEvents::POST_SUBMIT : FormEvents::POST_BIND;
-        $builder->addEventListener($event, array($validator, 'validate'));
+
+        $builder->addEventListener(FormEvents::POST_SUBMIT, array($validator, 'validate'));
     }
 
     /**
@@ -86,7 +78,7 @@ class CaptchaType extends AbstractType
         }
 
         $sessionKey = sprintf('%s%s', self::SESSION_KEY_PREFIX, $options['session_key']);
-        $isHuman    = false;
+        $isHuman = false;
 
         if ($options['humanity'] > 0) {
             $humanityKey = sprintf('%s_humanity', $sessionKey);
@@ -105,18 +97,18 @@ class CaptchaType extends AbstractType
         }
 
         $view->vars = array_merge($view->vars, array(
-            'captcha_width'     => $options['width'],
-            'captcha_height'    => $options['height'],
-            'reload'            => $options['reload'],
-            'image_id'          => uniqid('captcha_'),
-            'captcha_code'      => $this->generator->getCaptchaCode($options),
-            'value'             => '',
-            'is_human'          => $isHuman
+            'captcha_width' => $options['width'],
+            'captcha_height' => $options['height'],
+            'reload' => $options['reload'],
+            'image_id' => uniqid('captcha_'),
+            'captcha_code' => $this->generator->getCaptchaCode($options),
+            'value' => '',
+            'is_human' => $isHuman,
         ));
 
         $persistOptions = array();
         foreach (array('phrase', 'width', 'height', 'distortion', 'length',
-        'quality', 'background_color', 'background_images', 'text_color') as $key) {
+        'quality', 'background_color', 'background_images', 'text_color', ) as $key) {
             $persistOptions[$key] = $options[$key];
         }
 
@@ -132,36 +124,17 @@ class CaptchaType extends AbstractType
         $resolver->setDefaults($this->options);
     }
 
-    /**
-     * {@inheritdoc}
-     * BC for SF < 2.7
-     */
-    public function setDefaultOptions(OptionsResolverInterface $resolver)
+    public function getParent(): string
     {
-        $this->configureOptions($resolver);
+        return TextType::class;
     }
 
-    /**
-     * @return string
-     */
-    public function getParent()
-    {
-        // Not using ::class to support Symfony 2.8 w/ php>=5.3.9
-        return 'Symfony\Component\Form\Extension\Core\Type\TextType';
-    }
-
-    /**
-     * @return string
-     */
-    public function getName()
+    public function getName(): string
     {
         return $this->getBlockPrefix();
     }
 
-    /**
-     * @return string
-     */
-    public function getBlockPrefix()
+    public function getBlockPrefix(): string
     {
         return 'captcha';
     }
diff --git a/Validator/CaptchaValidator.php b/Validator/CaptchaValidator.php
index 7ee2a51..cdabc8e 100644
--- a/Validator/CaptchaValidator.php
+++ b/Validator/CaptchaValidator.php
@@ -1,73 +1,76 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Gregwar\CaptchaBundle\Validator;
 
 use Symfony\Component\HttpFoundation\Session\SessionInterface;
 use Symfony\Component\Form\FormError;
 use Symfony\Component\Form\FormEvent;
-use Symfony\Component\Translation\TranslatorInterface;
+use Symfony\Contracts\Translation\TranslatorInterface;
 
 /**
- * Captcha validator
+ * Captcha validator.
  *
  * @author Gregwar <g.passault@gmail.com>
  */
 class CaptchaValidator
 {
-    /**
-     * @var SessionInterface
-     */
+    /** @var SessionInterface */
     private $session;
 
     /**
-     * Session key to store the code
+     * Session key to store the code.
+     *
+     * @var string
      */
     private $key;
 
     /**
-     * Error message text for non-matching submissions
+     * Error message text for non-matching submissions.
+     *
+     * @var string
      */
     private $invalidMessage;
 
     /**
-     * Configuration parameter used to bypass a required code match
+     * Configuration parameter used to bypass a required code match.
+     *
+     * @var string
      */
     private $bypassCode;
 
     /**
-     * Number of form that the user can submit without captcha
+     * Number of form that the user can submit without captcha.
+     *
      * @var int
      */
     private $humanity;
 
     /**
-     * Translator
+     * Translator.
+     *
      * @var TranslatorInterface
      */
     private $translator;
 
-    /**
-     * @param TranslatorInterface $translator
-     * @param SessionInterface    $session
-     * @param string              $key
-     * @param string              $invalidMessage
-     * @param string              $bypassCode
-     * @param int                 $humanity
-     */
-    public function __construct(TranslatorInterface $translator, SessionInterface $session, $key, $invalidMessage, $bypassCode, $humanity)
-    {
-        $this->translator       = $translator;
-        $this->session          = $session;
-        $this->key              = $key;
-        $this->invalidMessage   = $invalidMessage;
-        $this->bypassCode       = (string)$bypassCode;
-        $this->humanity         = $humanity;
+    public function __construct(
+        TranslatorInterface $translator,
+        SessionInterface $session,
+        string $key,
+        string $invalidMessage,
+        ?string $bypassCode,
+        int $humanity
+    ) {
+        $this->translator = $translator;
+        $this->session = $session;
+        $this->key = $key;
+        $this->invalidMessage = $invalidMessage;
+        $this->bypassCode = $bypassCode;
+        $this->humanity = $humanity;
     }
 
-    /**
-     * @param FormEvent $event
-     */
-    public function validate(FormEvent $event)
+    public function validate(FormEvent $event): void
     {
         $form = $event->getForm();
 
@@ -77,12 +80,13 @@ class CaptchaValidator
         if ($this->humanity > 0) {
             $humanity = $this->getHumanity();
             if ($humanity > 0) {
-                $this->updateHumanity($humanity-1);
+                $this->updateHumanity($humanity - 1);
+
                 return;
             }
         }
 
-        if (!($code !== null && is_string($code) && ($this->compare($code, $expectedCode) || $this->compare($code, $this->bypassCode)))) {
+        if (!(null !== $code && is_string($code) && ($this->compare($code, $expectedCode) || $this->compare($code, $this->bypassCode)))) {
             $form->addError(new FormError($this->translator->trans($this->invalidMessage, array(), 'validators')));
         } else {
             if ($this->humanity > 0) {
@@ -92,13 +96,13 @@ class CaptchaValidator
 
         $this->session->remove($this->key);
 
-        if ($this->session->has($this->key . '_fingerprint')) {
-            $this->session->remove($this->key . '_fingerprint');
+        if ($this->session->has($this->key.'_fingerprint')) {
+            $this->session->remove($this->key.'_fingerprint');
         }
     }
 
     /**
-     * Retrieve the expected CAPTCHA code
+     * Retrieve the expected CAPTCHA code.
      *
      * @return mixed|null
      */
@@ -114,51 +118,39 @@ class CaptchaValidator
     }
 
     /**
-     * Retrieve the humanity
+     * Retrieve the humanity.
      *
      * @return mixed|null
      */
     protected function getHumanity()
     {
-        return $this->session->get($this->key . '_humanity', 0);
+        return $this->session->get($this->key.'_humanity', 0);
     }
 
-    /**
-     * Updates the humanity
-     */
-    protected function updateHumanity($newValue)
+    protected function updateHumanity(int $newValue): void
     {
         if ($newValue > 0) {
-            $this->session->set($this->key . '_humanity', $newValue);
+            $this->session->set($this->key.'_humanity', $newValue);
         } else {
-            $this->session->remove($this->key . '_humanity');
+            $this->session->remove($this->key.'_humanity');
         }
-
-        return null;
     }
 
-    /**
-     * Process the codes
-     *
-     * @param $code
-     *
-     * @return string
-     */
-    protected function niceize($code)
+    protected function niceize(string $code): string
     {
         return strtr(strtolower($code), 'oil', '01l');
     }
 
     /**
-     * Run a match comparison on the provided code and the expected code
+     * Run a match comparison on the provided code and the expected code.
      *
-     * @param $code
-     * @param $expectedCode
+     * @param string      $code
+     * @param string|null $expectedCode
      *
      * @return bool
      */
-    protected function compare($code, $expectedCode)
+    protected function compare($code, $expectedCode): bool
     {
-        return ($expectedCode !== null && is_string($expectedCode) && $this->niceize($code) == $this->niceize($expectedCode));
+        return null !== $expectedCode && is_string($expectedCode) && $this->niceize($code) == $this->niceize($expectedCode);
     }
 }
diff --git a/composer.json b/composer.json
index 703267b..d4351e7 100644
--- a/composer.json
+++ b/composer.json
@@ -17,15 +17,23 @@
         }
     ],
     "require": {
-        "php": ">=5.3.9",
+        "php": "^7.1.3",
+        "ext-gd": "*",
         "gregwar/captcha": "~1.1",
-        "symfony/framework-bundle": "~3.0|~4.0|~5.0",
-        "symfony/form": "~3.0|~4.0|~5.0",
-        "twig/twig": "^1.40|^2.9|^3"
+        "symfony/form": "~4.0|~5.0",
+        "symfony/framework-bundle": "~4.0|~5.0",
+        "symfony/translation": "~4.0|^5.0",
+        "twig/twig": "^2.10|^3.0"
     },
     "autoload": {
         "psr-4": {
             "Gregwar\\CaptchaBundle\\": "/"
         }
+    },
+    "config": {
+        "sort-packages": true
+    },
+    "require-dev": {
+        "symplify/easy-coding-standard": "^6.1"
     }
 }
diff --git a/ecs.yaml b/ecs.yaml
new file mode 100644
index 0000000..3c977fc
--- /dev/null
+++ b/ecs.yaml
@@ -0,0 +1,138 @@
+parameters:
+  exclude_files:
+    - 'vendor/*'
+    - 'LICENSE'
+    - 'README.md'
+
+services:
+  # PSR1
+  PhpCsFixer\Fixer\Basic\EncodingFixer: ~
+  PhpCsFixer\Fixer\PhpTag\FullOpeningTagFixer: ~
+
+  PhpCsFixer\Fixer\NamespaceNotation\BlankLineAfterNamespaceFixer: ~
+  PhpCsFixer\Fixer\ControlStructure\ElseifFixer: ~
+  PhpCsFixer\Fixer\FunctionNotation\FunctionDeclarationFixer: ~
+  PhpCsFixer\Fixer\Whitespace\IndentationTypeFixer: ~
+  PhpCsFixer\Fixer\Whitespace\LineEndingFixer: ~
+  PhpCsFixer\Fixer\Casing\ConstantCaseFixer: ~
+  PhpCsFixer\Fixer\Casing\LowercaseKeywordsFixer: ~
+  PhpCsFixer\Fixer\FunctionNotation\MethodArgumentSpaceFixer:
+    ensure_fully_multiline: true
+  PhpCsFixer\Fixer\ControlStructure\NoBreakCommentFixer: ~
+  PhpCsFixer\Fixer\PhpTag\NoClosingTagFixer: ~
+  PhpCsFixer\Fixer\FunctionNotation\NoSpacesAfterFunctionNameFixer: ~
+  PhpCsFixer\Fixer\Whitespace\NoSpacesInsideParenthesisFixer: ~
+  PhpCsFixer\Fixer\Whitespace\NoTrailingWhitespaceFixer: ~
+  PhpCsFixer\Fixer\Comment\NoTrailingWhitespaceInCommentFixer: ~
+  PhpCsFixer\Fixer\Whitespace\SingleBlankLineAtEofFixer: ~
+  PhpCsFixer\Fixer\ClassNotation\SingleClassElementPerStatementFixer:
+    elements:
+      - 'property'
+  PhpCsFixer\Fixer\Import\SingleImportPerStatementFixer: ~
+  PhpCsFixer\Fixer\Import\SingleLineAfterImportsFixer: ~
+  PhpCsFixer\Fixer\ControlStructure\SwitchCaseSemicolonToColonFixer: ~
+  PhpCsFixer\Fixer\ControlStructure\SwitchCaseSpaceFixer: ~
+  PhpCsFixer\Fixer\ClassNotation\VisibilityRequiredFixer: ~
+
+  PhpCsFixer\Fixer\Basic\BracesFixer:
+    allow_single_line_closure: true
+  PhpCsFixer\Fixer\PhpTag\BlankLineAfterOpeningTagFixer: ~
+  PhpCsFixer\Fixer\Operator\ConcatSpaceFixer:
+    spacing: none
+  PhpCsFixer\Fixer\Operator\NewWithBracesFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocAlignFixer:
+    tags:
+      - method
+      - param
+      - property
+      - return
+      - throws
+      - type
+      - var
+  PhpCsFixer\Fixer\Operator\BinaryOperatorSpacesFixer: ~
+  PhpCsFixer\Fixer\Operator\IncrementStyleFixer: ~
+  PhpCsFixer\Fixer\Operator\UnaryOperatorSpacesFixer: ~
+  PhpCsFixer\Fixer\Whitespace\BlankLineBeforeStatementFixer: ~
+  PhpCsFixer\Fixer\CastNotation\CastSpacesFixer: ~
+  PhpCsFixer\Fixer\LanguageConstruct\DeclareEqualNormalizeFixer: ~
+  PhpCsFixer\Fixer\FunctionNotation\FunctionTypehintSpaceFixer: ~
+  PhpCsFixer\Fixer\Comment\SingleLineCommentStyleFixer:
+    comment_types:
+      - hash
+  PhpCsFixer\Fixer\ControlStructure\IncludeFixer: ~
+  PhpCsFixer\Fixer\CastNotation\LowercaseCastFixer: ~
+  PhpCsFixer\Fixer\ClassNotation\ClassAttributesSeparationFixer:
+    elements:
+      - method
+  PhpCsFixer\Fixer\Casing\NativeFunctionCasingFixer: ~
+  PhpCsFixer\Fixer\ClassNotation\NoBlankLinesAfterClassOpeningFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\NoBlankLinesAfterPhpdocFixer: ~
+  PhpCsFixer\Fixer\Comment\NoEmptyCommentFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\NoEmptyPhpdocFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocSeparationFixer: ~
+  PhpCsFixer\Fixer\Semicolon\NoEmptyStatementFixer: ~
+  PhpCsFixer\Fixer\Whitespace\NoExtraBlankLinesFixer:
+    tokens:
+      - curly_brace_block
+      - extra
+      - parenthesis_brace_block
+      - square_brace_block
+      - throw
+      - use
+  PhpCsFixer\Fixer\NamespaceNotation\NoLeadingNamespaceWhitespaceFixer: ~
+  PhpCsFixer\Fixer\ArrayNotation\NoMultilineWhitespaceAroundDoubleArrowFixer: ~
+  PhpCsFixer\Fixer\CastNotation\NoShortBoolCastFixer: ~
+  PhpCsFixer\Fixer\Semicolon\NoSinglelineWhitespaceBeforeSemicolonsFixer: ~
+  PhpCsFixer\Fixer\Whitespace\NoSpacesAroundOffsetFixer: ~
+  PhpCsFixer\Fixer\ControlStructure\NoTrailingCommaInListCallFixer: ~
+  PhpCsFixer\Fixer\ArrayNotation\NoTrailingCommaInSinglelineArrayFixer: ~
+  PhpCsFixer\Fixer\ArrayNotation\TrailingCommaInMultilineArrayFixer: ~
+  PhpCsFixer\Fixer\ControlStructure\NoUnneededControlParenthesesFixer: ~
+  PhpCsFixer\Fixer\ArrayNotation\NoWhitespaceBeforeCommaInArrayFixer: ~
+  PhpCsFixer\Fixer\Whitespace\NoWhitespaceInBlankLineFixer: ~
+  PhpCsFixer\Fixer\ArrayNotation\NormalizeIndexBraceFixer: ~
+  PhpCsFixer\Fixer\Operator\ObjectOperatorWithoutWhitespaceFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocAnnotationWithoutDotFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocIndentFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocInlineTagFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocNoAccessFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocNoEmptyReturnFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocNoPackageFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocNoUselessInheritdocFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocReturnSelfReferenceFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocScalarFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocSingleLineVarSpacingFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocSummaryFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocToCommentFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocTrimFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocTypesFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocVarWithoutNameFixer: ~
+  PhpCsFixer\Fixer\FunctionNotation\ReturnTypeDeclarationFixer: ~
+  PhpCsFixer\Fixer\ClassNotation\SelfAccessorFixer: ~
+  PhpCsFixer\Fixer\CastNotation\ShortScalarCastFixer: ~
+  PhpCsFixer\Fixer\StringNotation\SingleQuoteFixer: ~
+  PhpCsFixer\Fixer\Semicolon\SpaceAfterSemicolonFixer: ~
+  PhpCsFixer\Fixer\Operator\StandardizeNotEqualsFixer: ~
+  PhpCsFixer\Fixer\Operator\TernaryOperatorSpacesFixer: ~
+  PhpCsFixer\Fixer\ArrayNotation\TrimArraySpacesFixer: ~
+  PhpCsFixer\Fixer\ArrayNotation\WhitespaceAfterCommaInArrayFixer: ~
+  PhpCsFixer\Fixer\ClassNotation\ClassDefinitionFixer:
+    singleLine: true
+  PhpCsFixer\Fixer\Casing\MagicConstantCasingFixer: ~
+  PhpCsFixer\Fixer\Alias\NoMixedEchoPrintFixer:
+    use: echo
+  PhpCsFixer\Fixer\Import\NoLeadingImportSlashFixer: ~
+  PhpCsFixer\Fixer\Import\NoUnusedImportsFixer: ~
+  PhpCsFixer\Fixer\PhpUnit\PhpUnitFqcnAnnotationFixer: ~
+  PhpCsFixer\Fixer\Phpdoc\PhpdocNoAliasTagFixer: ~
+  PhpCsFixer\Fixer\ClassNotation\ProtectedToPrivateFixer: ~
+  PhpCsFixer\Fixer\NamespaceNotation\SingleBlankLineBeforeNamespaceFixer: ~
+
+  # new since PHP-CS-Fixer 2.6
+  PhpCsFixer\Fixer\ControlStructure\NoUnneededCurlyBracesFixer: ~
+  PhpCsFixer\Fixer\ClassNotation\NoUnneededFinalMethodFixer: ~
+  PhpCsFixer\Fixer\Semicolon\SemicolonAfterInstructionFixer: ~
+  PhpCsFixer\Fixer\ControlStructure\YodaStyleFixer: ~
+
+  # new since 2.11
+  PhpCsFixer\Fixer\Operator\StandardizeIncrementFixer: ~