diff --git a/src/Sculpin/Bundle/ContentTypesBundle/Command/ContentCreateCommand.php b/src/Sculpin/Bundle/ContentTypesBundle/Command/ContentCreateCommand.php
index 0fd3bb58..9546463d 100644
--- a/src/Sculpin/Bundle/ContentTypesBundle/Command/ContentCreateCommand.php
+++ b/src/Sculpin/Bundle/ContentTypesBundle/Command/ContentCreateCommand.php
@@ -28,12 +28,12 @@
  */
 class ContentCreateCommand extends AbstractCommand
 {
-    const DIRECTORY_FLAG = '_directory_';
+    private const DIRECTORY_FLAG = '_directory_';
 
     /**
      * {@inheritdoc}
      */
-    protected function configure()
+    protected function configure(): void
     {
         $prefix = $this->isStandaloneSculpin() ? '' : 'sculpin:';
 
@@ -72,7 +72,7 @@ protected function configure()
     /**
      * {@inheritdoc}
      */
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): void
     {
         $pluralType   = $input->getArgument('type');
         $singularType = Inflector::singularize($pluralType);
@@ -109,7 +109,7 @@ protected function execute(InputInterface $input, OutputInterface $output)
         }
     }
 
-    protected function generateBoilerplateManifest($plural, $singular, array $taxonomies = []): array
+    protected function generateBoilerplateManifest(string $plural, string $singular, array $taxonomies = []): array
     {
         $app = $this->getApplication();
         if (!$app instanceof Application) {
@@ -153,7 +153,7 @@ protected function generateBoilerplateManifest($plural, $singular, array $taxono
         return $manifest;
     }
 
-    protected function getOutputMessage($type, $singularType, $taxonomies = [])
+    protected function getOutputMessage(string $type, string $singularType, array $taxonomies = []): string
     {
         $outputMessage = <<<EOT
 =============================================
@@ -181,7 +181,7 @@ protected function getOutputMessage($type, $singularType, $taxonomies = [])
         return $outputMessage;
     }
 
-    protected function getIndexTemplate($plural, $singular)
+    protected function getIndexTemplate(string $plural, string $singular)
     {
         $title = ucfirst($plural);
 
@@ -214,7 +214,7 @@ protected function getIndexTemplate($plural, $singular)
 EOT;
     }
 
-    protected function getViewTemplate($plural, $singular, $taxonomies = [])
+    protected function getViewTemplate(string $plural, string $singular, array $taxonomies = []): string
     {
         $output = <<<EOT
 {% extends 'default' %}
@@ -264,8 +264,12 @@ protected function getViewTemplate($plural, $singular, $taxonomies = [])
         return $output;
     }
 
-    protected function getTaxonomyIndexTemplate($plural, $singular, $taxonomy, $singularTaxonomy)
-    {
+    protected function getTaxonomyIndexTemplate(
+        string $plural,
+        string $singular,
+        string $taxonomy,
+        string $singularTaxonomy
+    ): string {
         $title = ucfirst($taxonomy);
 
         return <<<EOT
@@ -283,8 +287,12 @@ protected function getTaxonomyIndexTemplate($plural, $singular, $taxonomy, $sing
 EOT;
     }
 
-    protected function getTaxonomyViewTemplate($plural, $singular, $taxonomy, $singularTaxonomy)
-    {
+    protected function getTaxonomyViewTemplate(
+        string $plural,
+        string $singular,
+        string $taxonomy,
+        string $singularTaxonomy
+    ): string {
         $title = ucfirst($plural);
 
         return <<<EOT
diff --git a/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/Compiler/MapPass.php b/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/Compiler/MapPass.php
index 09a9d072..af9cb099 100644
--- a/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/Compiler/MapPass.php
+++ b/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/Compiler/MapPass.php
@@ -19,7 +19,7 @@
 
 class MapPass implements CompilerPassInterface
 {
-    public function process(ContainerBuilder $container)
+    public function process(ContainerBuilder $container): void
     {
         $typesId = self::generateId('types');
         $types = $container->getParameter($typesId);
@@ -41,12 +41,12 @@ public function process(ContainerBuilder $container)
         }
     }
 
-    private static function generateId($value)
+    private static function generateId(string $value): string
     {
         return implode('.', ['sculpin_content_types', $value]);
     }
 
-    private static function generateTypesId($type, $value)
+    private static function generateTypesId(string $type, string $value): string
     {
         return implode('.', ['sculpin_content_types.types', $type, $value]);
     }
diff --git a/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/Configuration.php b/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/Configuration.php
index af7671bc..6219e9f9 100644
--- a/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/Configuration.php
+++ b/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/Configuration.php
@@ -26,7 +26,7 @@ class Configuration implements ConfigurationInterface
     /**
     * {@inheritdoc}
     */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder();
 
diff --git a/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/SculpinContentTypesExtension.php b/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/SculpinContentTypesExtension.php
index 375e6182..d1726bcc 100644
--- a/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/SculpinContentTypesExtension.php
+++ b/src/Sculpin/Bundle/ContentTypesBundle/DependencyInjection/SculpinContentTypesExtension.php
@@ -273,17 +273,17 @@ public function load(array $configs, ContainerBuilder $container)
         }
     }
 
-    private static function generatePlaceholder($value)
+    private static function generatePlaceholder(string $value): string
     {
         return '%'.$value.'%';
     }
 
-    private static function generateId($value)
+    private static function generateId(string $value): string
     {
         return implode('.', ['sculpin_content_types', $value]);
     }
 
-    private static function generateTypesId($type, $value)
+    private static function generateTypesId(string $type, string $value)
     {
         return implode('.', ['sculpin_content_types.types', $type, $value]);
     }
diff --git a/src/Sculpin/Bundle/ContentTypesBundle/SculpinContentTypesBundle.php b/src/Sculpin/Bundle/ContentTypesBundle/SculpinContentTypesBundle.php
index bed0d2fb..18f97617 100644
--- a/src/Sculpin/Bundle/ContentTypesBundle/SculpinContentTypesBundle.php
+++ b/src/Sculpin/Bundle/ContentTypesBundle/SculpinContentTypesBundle.php
@@ -27,7 +27,7 @@ class SculpinContentTypesBundle extends Bundle
     /**
      * {@inheritdoc}
      */
-    public function build(ContainerBuilder $container)
+    public function build(ContainerBuilder $container): void
     {
         $container->addCompilerPass(new MapPass);
     }
diff --git a/src/Sculpin/Bundle/MarkdownBundle/DependencyInjection/Configuration.php b/src/Sculpin/Bundle/MarkdownBundle/DependencyInjection/Configuration.php
index acb76886..3f7e6d70 100644
--- a/src/Sculpin/Bundle/MarkdownBundle/DependencyInjection/Configuration.php
+++ b/src/Sculpin/Bundle/MarkdownBundle/DependencyInjection/Configuration.php
@@ -26,7 +26,7 @@ class Configuration implements ConfigurationInterface
     /**
     * {@inheritdoc}
     */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder;
 
diff --git a/src/Sculpin/Bundle/MarkdownBundle/DependencyInjection/SculpinMarkdownExtension.php b/src/Sculpin/Bundle/MarkdownBundle/DependencyInjection/SculpinMarkdownExtension.php
index c77aeb77..21ce1403 100644
--- a/src/Sculpin/Bundle/MarkdownBundle/DependencyInjection/SculpinMarkdownExtension.php
+++ b/src/Sculpin/Bundle/MarkdownBundle/DependencyInjection/SculpinMarkdownExtension.php
@@ -28,7 +28,7 @@ class SculpinMarkdownExtension extends Extension
     /**
      * {@inheritdoc}
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $configuration = new Configuration;
         $config = $this->processConfiguration($configuration, $configs);
diff --git a/src/Sculpin/Bundle/MarkdownBundle/MarkdownConverter.php b/src/Sculpin/Bundle/MarkdownBundle/MarkdownConverter.php
index 05a0f2ad..fcec0ebe 100644
--- a/src/Sculpin/Bundle/MarkdownBundle/MarkdownConverter.php
+++ b/src/Sculpin/Bundle/MarkdownBundle/MarkdownConverter.php
@@ -18,6 +18,7 @@
 use Sculpin\Core\Converter\ParserInterface;
 use Sculpin\Core\Event\SourceSetEvent;
 use Sculpin\Core\Sculpin;
+use Sculpin\Core\Source\SourceInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Michelf\Markdown;
 
@@ -68,7 +69,7 @@ public function convert(ConverterContextInterface $converterContext): void
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             Sculpin::EVENT_BEFORE_RUN => 'beforeRun',
@@ -80,8 +81,9 @@ public static function getSubscribedEvents()
      *
      * @param SourceSetEvent $sourceSetEvent Source Set Event
      */
-    public function beforeRun(SourceSetEvent $sourceSetEvent)
+    public function beforeRun(SourceSetEvent $sourceSetEvent): void
     {
+        /** @var SourceInterface $source */
         foreach ($sourceSetEvent->updatedSources() as $source) {
             foreach ($this->extensions as $extension) {
                 if (fnmatch("*.{$extension}", $source->filename())) {
@@ -99,7 +101,7 @@ public function beforeRun(SourceSetEvent $sourceSetEvent)
      * @param string $headerText raw markdown input for the header name
      * @return string
      */
-    public function generateHeaderId($headerText)
+    public function generateHeaderId(string $headerText): string
     {
 
         // $headerText is completely raw markdown input. We need to strip it
diff --git a/src/Sculpin/Bundle/MarkdownBundle/SculpinMarkdownBundle.php b/src/Sculpin/Bundle/MarkdownBundle/SculpinMarkdownBundle.php
index 3d0fd79c..406572b0 100644
--- a/src/Sculpin/Bundle/MarkdownBundle/SculpinMarkdownBundle.php
+++ b/src/Sculpin/Bundle/MarkdownBundle/SculpinMarkdownBundle.php
@@ -22,5 +22,5 @@
  */
 class SculpinMarkdownBundle extends Bundle
 {
-    const CONVERTER_NAME = 'markdown';
+    public const CONVERTER_NAME = 'markdown';
 }
diff --git a/src/Sculpin/Bundle/MarkdownTwigCompatBundle/ConvertListener.php b/src/Sculpin/Bundle/MarkdownTwigCompatBundle/ConvertListener.php
index f0e09d9d..3e82064a 100644
--- a/src/Sculpin/Bundle/MarkdownTwigCompatBundle/ConvertListener.php
+++ b/src/Sculpin/Bundle/MarkdownTwigCompatBundle/ConvertListener.php
@@ -54,7 +54,7 @@ class ConvertListener implements EventSubscriberInterface
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             Sculpin::EVENT_BEFORE_CONVERT => 'beforeConvert',
@@ -67,7 +67,7 @@ public static function getSubscribedEvents()
      *
      * @param ConvertEvent $convertEvent Convert Event
      */
-    public function beforeConvert(ConvertEvent $convertEvent)
+    public function beforeConvert(ConvertEvent $convertEvent): void
     {
         if ($convertEvent->isHandledBy(SculpinMarkdownBundle::CONVERTER_NAME, SculpinTwigBundle::FORMATTER_NAME)) {
             $content = $convertEvent->source()->content();
@@ -88,7 +88,7 @@ public function beforeConvert(ConvertEvent $convertEvent)
      *
      * @param ConvertEvent $convertEvent Convert event
      */
-    public function afterConvert(ConvertEvent $convertEvent)
+    public function afterConvert(ConvertEvent $convertEvent): void
     {
         if ($convertEvent->isHandledBy(SculpinMarkdownBundle::CONVERTER_NAME, SculpinTwigBundle::FORMATTER_NAME)) {
             $content = $convertEvent->source()->content();
diff --git a/src/Sculpin/Bundle/MarkdownTwigCompatBundle/DependencyInjection/SculpinMarkdownTwigCompatExtension.php b/src/Sculpin/Bundle/MarkdownTwigCompatBundle/DependencyInjection/SculpinMarkdownTwigCompatExtension.php
index e5ff88f9..304cf00d 100644
--- a/src/Sculpin/Bundle/MarkdownTwigCompatBundle/DependencyInjection/SculpinMarkdownTwigCompatExtension.php
+++ b/src/Sculpin/Bundle/MarkdownTwigCompatBundle/DependencyInjection/SculpinMarkdownTwigCompatExtension.php
@@ -28,7 +28,7 @@ class SculpinMarkdownTwigCompatExtension extends Extension
     /**
      * {@inheritdoc}
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $loader = new Loader\XmlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
         $loader->load('services.xml');
diff --git a/src/Sculpin/Bundle/PaginationBundle/DependencyInjection/Configuration.php b/src/Sculpin/Bundle/PaginationBundle/DependencyInjection/Configuration.php
index 7e68602f..00b0fc14 100644
--- a/src/Sculpin/Bundle/PaginationBundle/DependencyInjection/Configuration.php
+++ b/src/Sculpin/Bundle/PaginationBundle/DependencyInjection/Configuration.php
@@ -26,7 +26,7 @@ class Configuration implements ConfigurationInterface
     /**
     * {@inheritdoc}
     */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder;
 
diff --git a/src/Sculpin/Bundle/PaginationBundle/DependencyInjection/SculpinPaginationExtension.php b/src/Sculpin/Bundle/PaginationBundle/DependencyInjection/SculpinPaginationExtension.php
index 9980e88f..0d700e09 100644
--- a/src/Sculpin/Bundle/PaginationBundle/DependencyInjection/SculpinPaginationExtension.php
+++ b/src/Sculpin/Bundle/PaginationBundle/DependencyInjection/SculpinPaginationExtension.php
@@ -28,7 +28,7 @@ class SculpinPaginationExtension extends Extension
     /**
      * {@inheritdoc}
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $configuration = new Configuration;
         $config = $this->processConfiguration($configuration, $configs);
diff --git a/src/Sculpin/Bundle/PaginationBundle/PaginationGenerator.php b/src/Sculpin/Bundle/PaginationBundle/PaginationGenerator.php
index 73c3d27b..d550605e 100644
--- a/src/Sculpin/Bundle/PaginationBundle/PaginationGenerator.php
+++ b/src/Sculpin/Bundle/PaginationBundle/PaginationGenerator.php
@@ -56,7 +56,7 @@ class PaginationGenerator implements GeneratorInterface
     public function __construct(
         DataProviderManager $dataProviderManager,
         SourcePermalinkFactory $permalinkFactory,
-        $maxPerPage
+        int $maxPerPage
     ) {
         $this->dataProviderManager = $dataProviderManager;
         $this->permalinkFactory = $permalinkFactory;
diff --git a/src/Sculpin/Bundle/PostsBundle/DependencyInjection/Configuration.php b/src/Sculpin/Bundle/PostsBundle/DependencyInjection/Configuration.php
index 00d4e393..7c2ce2f3 100644
--- a/src/Sculpin/Bundle/PostsBundle/DependencyInjection/Configuration.php
+++ b/src/Sculpin/Bundle/PostsBundle/DependencyInjection/Configuration.php
@@ -26,7 +26,7 @@ class Configuration implements ConfigurationInterface
     /**
     * {@inheritdoc}
     */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder;
 
diff --git a/src/Sculpin/Bundle/PostsBundle/DependencyInjection/SculpinPostsExtension.php b/src/Sculpin/Bundle/PostsBundle/DependencyInjection/SculpinPostsExtension.php
index 64af5994..245e8919 100644
--- a/src/Sculpin/Bundle/PostsBundle/DependencyInjection/SculpinPostsExtension.php
+++ b/src/Sculpin/Bundle/PostsBundle/DependencyInjection/SculpinPostsExtension.php
@@ -27,7 +27,7 @@ class SculpinPostsExtension extends Extension
     /**
      * {@inheritdoc}
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $configuration = new Configuration;
         $config = $this->processConfiguration($configuration, $configs);
diff --git a/src/Sculpin/Bundle/SculpinBundle/Command/AbstractCommand.php b/src/Sculpin/Bundle/SculpinBundle/Command/AbstractCommand.php
index d011b717..7420a4be 100644
--- a/src/Sculpin/Bundle/SculpinBundle/Command/AbstractCommand.php
+++ b/src/Sculpin/Bundle/SculpinBundle/Command/AbstractCommand.php
@@ -27,7 +27,7 @@ abstract class AbstractCommand extends ContainerAwareCommand
      *
      * @return bool
      */
-    protected function isStandaloneSculpin()
+    protected function isStandaloneSculpin(): bool
     {
         return class_exists('Sculpin\\Bundle\\StandaloneBundle\\SculpinStandaloneBundle', false);
     }
diff --git a/src/Sculpin/Bundle/SculpinBundle/Command/ContainerDebugCommand.php b/src/Sculpin/Bundle/SculpinBundle/Command/ContainerDebugCommand.php
index 2afa3f56..2226cffb 100644
--- a/src/Sculpin/Bundle/SculpinBundle/Command/ContainerDebugCommand.php
+++ b/src/Sculpin/Bundle/SculpinBundle/Command/ContainerDebugCommand.php
@@ -50,7 +50,7 @@ class ContainerDebugCommand extends ContainerAwareCommand
     /**
      * {@inheritdoc}
      */
-    protected function configure()
+    protected function configure(): void
     {
         $this
             ->setName('container:debug')
@@ -127,7 +127,7 @@ protected function configure()
      *
      * @throws \LogicException
      */
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): void
     {
         $this->validateInput($input);
 
@@ -207,7 +207,7 @@ protected function outputServices(
         $serviceIds,
         $showPrivate = false,
         $showTagAttributes = null
-    ) {
+    ): void {
         // set the label to specify public or public+private
         if ($showPrivate) {
             $label = '<comment>Public</comment> and <comment>private</comment> services';
@@ -322,7 +322,7 @@ protected function outputServices(
         }
     }
 
-    protected function buildArgumentsArray($serviceId, $className, array $tagAttributes = [])
+    protected function buildArgumentsArray($serviceId, $className, array $tagAttributes = []): array
     {
         $arguments = [$serviceId];
         foreach ($tagAttributes as $tagAttribute) {
@@ -336,7 +336,7 @@ protected function buildArgumentsArray($serviceId, $className, array $tagAttribu
     /**
      * Renders detailed service information about one service
      */
-    protected function outputService(OutputInterface $output, $serviceId)
+    protected function outputService(OutputInterface $output, string $serviceId)
     {
         $definition = $this->resolveServiceDefinition($serviceId);
 
@@ -389,7 +389,7 @@ function ($key, $value) {
         }
     }
 
-    protected function outputParameters(OutputInterface $output, $parameters)
+    protected function outputParameters(OutputInterface $output, array $parameters): void
     {
         $output->writeln($this->getHelper('formatter')->formatSection('container', 'List of parameters'));
 
@@ -437,6 +437,7 @@ protected function outputParameters(OutputInterface $output, $parameters)
      * @param string $serviceId The service id to resolve
      *
      * @return Definition|Alias
+     * @throws \Exception
      */
     protected function resolveServiceDefinition($serviceId)
     {
@@ -460,9 +461,11 @@ protected function resolveServiceDefinition($serviceId)
      * Renders list of tagged services grouped by tag
      *
      * @param OutputInterface $output
-     * @param bool            $showPrivate
+     * @param bool $showPrivate
+     *
+     * @throws \Exception
      */
-    protected function outputTags(OutputInterface $output, $showPrivate = false)
+    protected function outputTags(OutputInterface $output, bool $showPrivate = false): void
     {
         $container = $this->getContainer();
         if (! $container instanceof ContainerBuilder) {
diff --git a/src/Sculpin/Bundle/SculpinBundle/Command/GenerateCommand.php b/src/Sculpin/Bundle/SculpinBundle/Command/GenerateCommand.php
index 56e84b6d..8dfce12a 100644
--- a/src/Sculpin/Bundle/SculpinBundle/Command/GenerateCommand.php
+++ b/src/Sculpin/Bundle/SculpinBundle/Command/GenerateCommand.php
@@ -32,7 +32,7 @@ class GenerateCommand extends AbstractCommand
     /**
      * {@inheritdoc}
      */
-    protected function configure()
+    protected function configure(): void
     {
         $prefix = $this->isStandaloneSculpin() ? '' : 'sculpin:';
 
@@ -72,7 +72,7 @@ protected function configure()
     /**
      * {@inheritdoc}
      */
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): void
     {
         $application = $this->getApplication();
         if ($application instanceof Application) {
@@ -109,7 +109,7 @@ protected function execute(InputInterface $input, OutputInterface $output)
                 $docroot,
                 $kernel->getEnvironment(),
                 $kernel->isDebug(),
-                $input->getOption('port')
+                (int) $input->getOption('port')
             );
 
             if ($watch) {
@@ -142,7 +142,7 @@ protected function execute(InputInterface $input, OutputInterface $output)
      * @param OutputInterface $output An OutputInterface instance
      * @param string          $dir    The directory to remove
      */
-    protected function clean(InputInterface $input, OutputInterface $output, $dir)
+    protected function clean(InputInterface $input, OutputInterface $output, string $dir): void
     {
         $fileSystem = $this->getContainer()->get('filesystem');
         if ($fileSystem->exists($dir)) {
diff --git a/src/Sculpin/Bundle/SculpinBundle/Command/ServeCommand.php b/src/Sculpin/Bundle/SculpinBundle/Command/ServeCommand.php
index e03607d5..0dcdef79 100644
--- a/src/Sculpin/Bundle/SculpinBundle/Command/ServeCommand.php
+++ b/src/Sculpin/Bundle/SculpinBundle/Command/ServeCommand.php
@@ -28,7 +28,7 @@ class ServeCommand extends AbstractCommand
     /**
      * {@inheritdoc}
      */
-    protected function configure()
+    protected function configure(): void
     {
         $prefix = $this->isStandaloneSculpin() ? '' : 'sculpin:';
 
@@ -48,7 +48,7 @@ protected function configure()
     /**
      * {@inheritdoc}
      */
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): void
     {
         $docroot = $this->getContainer()->getParameter('sculpin.output_dir');
         $kernel = $this->getContainer()->get('kernel');
@@ -58,7 +58,7 @@ protected function execute(InputInterface $input, OutputInterface $output)
             $docroot,
             $kernel->getEnvironment(),
             $kernel->isDebug(),
-            $input->getOption('port')
+            (int) $input->getOption('port')
         );
 
         $httpServer->run();
diff --git a/src/Sculpin/Bundle/SculpinBundle/Console/Application.php b/src/Sculpin/Bundle/SculpinBundle/Console/Application.php
index d603bd3b..8bd45ecc 100644
--- a/src/Sculpin/Bundle/SculpinBundle/Console/Application.php
+++ b/src/Sculpin/Bundle/SculpinBundle/Console/Application.php
@@ -94,7 +94,7 @@ public function __construct(KernelInterface $kernel)
     /**
      * {@inheritDoc}
      */
-    public function run(InputInterface $input = null, OutputInterface $output = null)
+    public function run(InputInterface $input = null, OutputInterface $output = null): int
     {
         if (null === $output) {
             $styles = [
@@ -111,7 +111,7 @@ public function run(InputInterface $input = null, OutputInterface $output = null
     /**
      * {@inheritdoc}
      */
-    public function doRun(InputInterface $input, OutputInterface $output)
+    public function doRun(InputInterface $input, OutputInterface $output): int
     {
         if ($input->hasParameterOption('--git-version')) {
             $output->writeln(Sculpin::GIT_VERSION);
@@ -137,7 +137,7 @@ public function doRun(InputInterface $input, OutputInterface $output)
         return $exitCode;
     }
 
-    public function getMissingSculpinBundlesMessages()
+    public function getMissingSculpinBundlesMessages(): array
     {
         $messages = [];
 
@@ -159,12 +159,12 @@ public function getMissingSculpinBundlesMessages()
      *
      * @return KernelInterface
      */
-    public function getKernel()
+    public function getKernel(): KernelInterface
     {
         return $this->kernel;
     }
 
-    protected function registerCommands()
+    protected function registerCommands(): void
     {
         $this->kernel->boot();
 
@@ -201,7 +201,7 @@ protected function registerCommands()
         }
     }
 
-    private function renderRegistrationErrors(InputInterface $input, OutputInterface $output)
+    private function renderRegistrationErrors(InputInterface $input, OutputInterface $output): void
     {
         if ($output instanceof ConsoleOutputInterface) {
             $output = $output->getErrorOutput();
diff --git a/src/Sculpin/Bundle/SculpinBundle/DependencyInjection/Configuration.php b/src/Sculpin/Bundle/SculpinBundle/DependencyInjection/Configuration.php
index 1e3c02fb..e2961df9 100644
--- a/src/Sculpin/Bundle/SculpinBundle/DependencyInjection/Configuration.php
+++ b/src/Sculpin/Bundle/SculpinBundle/DependencyInjection/Configuration.php
@@ -26,7 +26,7 @@ class Configuration implements ConfigurationInterface
     /**
     * {@inheritdoc}
     */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder;
 
diff --git a/src/Sculpin/Bundle/SculpinBundle/DependencyInjection/SculpinExtension.php b/src/Sculpin/Bundle/SculpinBundle/DependencyInjection/SculpinExtension.php
index 18cbc720..78a00034 100644
--- a/src/Sculpin/Bundle/SculpinBundle/DependencyInjection/SculpinExtension.php
+++ b/src/Sculpin/Bundle/SculpinBundle/DependencyInjection/SculpinExtension.php
@@ -28,7 +28,7 @@ class SculpinExtension extends Extension
     /**
      * {@inheritdoc}
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $configuration = new Configuration;
         $config = $this->processConfiguration($configuration, $configs);
diff --git a/src/Sculpin/Bundle/SculpinBundle/HttpKernel/AbstractKernel.php b/src/Sculpin/Bundle/SculpinBundle/HttpKernel/AbstractKernel.php
index 0189474a..4c41c562 100644
--- a/src/Sculpin/Bundle/SculpinBundle/HttpKernel/AbstractKernel.php
+++ b/src/Sculpin/Bundle/SculpinBundle/HttpKernel/AbstractKernel.php
@@ -15,6 +15,7 @@
 
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\Config\Loader\LoaderInterface;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
 use Symfony\Component\HttpKernel\Kernel;
 
@@ -32,7 +33,7 @@ abstract class AbstractKernel extends Kernel
     /**
      * {@inheritdoc}
      */
-    public function __construct($environment, $debug, $overrides = null)
+    public function __construct(string $environment, bool $debug, ?array $overrides = [])
     {
         $projectDir = $overrides['projectDir'] ?? null;
         if (null !== $projectDir) {
@@ -51,7 +52,7 @@ public function __construct($environment, $debug, $overrides = null)
     /**
      * {@inheritdoc}
      */
-    protected function getKernelParameters()
+    protected function getKernelParameters(): array
     {
         if (null === $this->projectDir) {
             $this->projectDir = dirname($this->rootDir);
@@ -66,7 +67,7 @@ protected function getKernelParameters()
     /**
      * {@inheritdoc}
      */
-    public function registerBundles()
+    public function registerBundles(): array
     {
         $bundles = [
             new \Sculpin\Bundle\StandaloneBundle\SculpinStandaloneBundle,
@@ -110,7 +111,7 @@ public function registerContainerConfiguration(LoaderInterface $loader)
     /**
      * {@inheritdoc}
      */
-    public function boot()
+    public function boot(): void
     {
         if (true === $this->booted) {
             return;
@@ -124,7 +125,7 @@ public function boot()
     /**
      * {@inheritdoc}
      */
-    protected function buildContainer()
+    protected function buildContainer(): ContainerBuilder
     {
         $container = $this->getContainerBuilder();
         $container->addObjectResource($this);
@@ -145,7 +146,7 @@ protected function buildContainer()
     /**
      * {@inheritdoc}
      */
-    protected function initializeContainer()
+    protected function initializeContainer(): void
     {
         $container = $this->buildContainer();
         $container->set('kernel', $this);
@@ -163,7 +164,7 @@ protected function initializeContainer()
      *
      * @return array
      */
-    public function getMissingSculpinBundles()
+    public function getMissingSculpinBundles(): array
     {
         return $this->missingSculpinBundles;
     }
@@ -173,5 +174,5 @@ public function getMissingSculpinBundles()
      *
      * @return array
      */
-    abstract protected function getAdditionalSculpinBundles();
+    abstract protected function getAdditionalSculpinBundles(): array;
 }
diff --git a/src/Sculpin/Bundle/SculpinBundle/HttpKernel/DefaultKernel.php b/src/Sculpin/Bundle/SculpinBundle/HttpKernel/DefaultKernel.php
index 2612b787..db74b00d 100644
--- a/src/Sculpin/Bundle/SculpinBundle/HttpKernel/DefaultKernel.php
+++ b/src/Sculpin/Bundle/SculpinBundle/HttpKernel/DefaultKernel.php
@@ -23,7 +23,7 @@ class DefaultKernel extends AbstractKernel
     /**
      * {@inheritdoc}
      */
-    protected function getAdditionalSculpinBundles()
+    protected function getAdditionalSculpinBundles(): array
     {
         return [];
     }
diff --git a/src/Sculpin/Bundle/SculpinBundle/HttpKernel/KernelFactory.php b/src/Sculpin/Bundle/SculpinBundle/HttpKernel/KernelFactory.php
index 02a6ce05..f561abe5 100644
--- a/src/Sculpin/Bundle/SculpinBundle/HttpKernel/KernelFactory.php
+++ b/src/Sculpin/Bundle/SculpinBundle/HttpKernel/KernelFactory.php
@@ -14,6 +14,7 @@
 namespace Sculpin\Bundle\SculpinBundle\HttpKernel;
 
 use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\HttpKernel\Kernel;
 
 /**
  * Kernel Factory
@@ -27,9 +28,9 @@ class KernelFactory
      *
      * @param InputInterface $input Input
      *
-     * @return \Symfony\Component\HttpKernel\Kernel
+     * @return Kernel
      */
-    public static function create(InputInterface $input)
+    public static function create(InputInterface $input): Kernel
     {
         $env = $input->getParameterOption(['--env', '-e'], getenv('SCULPIN_DEBUG') ?: 'dev');
         $debug = (
diff --git a/src/Sculpin/Bundle/SculpinBundle/HttpServer/HttpServer.php b/src/Sculpin/Bundle/SculpinBundle/HttpServer/HttpServer.php
index f005702e..99545a64 100644
--- a/src/Sculpin/Bundle/SculpinBundle/HttpServer/HttpServer.php
+++ b/src/Sculpin/Bundle/SculpinBundle/HttpServer/HttpServer.php
@@ -43,7 +43,7 @@ class HttpServer
      * @param bool            $debug   Debug
      * @param int             $port    Port
      */
-    public function __construct(OutputInterface $output, $docroot, $env, $debug, $port = null)
+    public function __construct(OutputInterface $output, string $docroot, string $env, bool $debug, ?int $port = null)
     {
         $repository = new PhpRepository;
 
@@ -103,7 +103,7 @@ public function __construct(OutputInterface $output, $docroot, $env, $debug, $po
      * @param int      $interval Interval
      * @param callable $callback Callback
      */
-    public function addPeriodicTimer($interval, $callback)
+    public function addPeriodicTimer(int $interval, callable $callback): void
     {
         $this->loop->addPeriodicTimer($interval, $callback);
     }
@@ -111,7 +111,7 @@ public function addPeriodicTimer($interval, $callback)
     /**
      * Run server
      */
-    public function run()
+    public function run(): void
     {
         $this->output->writeln(sprintf(
             'Starting Sculpin server for the <info>%s</info> environment with debug <info>%s</info>',
@@ -132,10 +132,10 @@ public function run()
      * Log a request
      *
      * @param OutputInterface           $output       Output
-     * @param string                    $responseCode Response code
+     * @param int                       $responseCode Response code
      * @param ServerRequestInterface    $request      Request
      */
-    public static function logRequest(OutputInterface $output, $responseCode, ServerRequestInterface $request)
+    public static function logRequest(OutputInterface $output, int $responseCode, ServerRequestInterface $request): void
     {
         $wrapOpen  = '';
         $wrapClose = '';
diff --git a/src/Sculpin/Bundle/SculpinBundle/SculpinBundle.php b/src/Sculpin/Bundle/SculpinBundle/SculpinBundle.php
index a975f75d..9a5ac239 100644
--- a/src/Sculpin/Bundle/SculpinBundle/SculpinBundle.php
+++ b/src/Sculpin/Bundle/SculpinBundle/SculpinBundle.php
@@ -35,7 +35,7 @@ class SculpinBundle extends Bundle
     /**
      * {@inheritdoc}
      */
-    public function build(ContainerBuilder $container)
+    public function build(ContainerBuilder $container): void
     {
         $container->addCompilerPass(new ConverterManagerPass);
         $container->addCompilerPass(new DataProviderManagerPass);
diff --git a/src/Sculpin/Bundle/StandaloneBundle/Command/CacheClearCommand.php b/src/Sculpin/Bundle/StandaloneBundle/Command/CacheClearCommand.php
index 2f802f71..345eebee 100644
--- a/src/Sculpin/Bundle/StandaloneBundle/Command/CacheClearCommand.php
+++ b/src/Sculpin/Bundle/StandaloneBundle/Command/CacheClearCommand.php
@@ -51,7 +51,7 @@ protected function configure()
     /**
      * {@inheritdoc}
      */
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): void
     {
         $cacheDir = $this->getContainer()->getParameter('kernel.cache_dir');
         $filesystem   = $this->getContainer()->get('filesystem');
diff --git a/src/Sculpin/Bundle/StandaloneBundle/DependencyInjection/SculpinStandaloneExtension.php b/src/Sculpin/Bundle/StandaloneBundle/DependencyInjection/SculpinStandaloneExtension.php
index e06843e4..e07d7dd0 100644
--- a/src/Sculpin/Bundle/StandaloneBundle/DependencyInjection/SculpinStandaloneExtension.php
+++ b/src/Sculpin/Bundle/StandaloneBundle/DependencyInjection/SculpinStandaloneExtension.php
@@ -28,7 +28,7 @@ class SculpinStandaloneExtension extends Extension
     /**
      * {@inheritdoc}
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $loader = new Loader\XmlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
         $loader->load('services.xml');
diff --git a/src/Sculpin/Bundle/StandaloneBundle/SculpinStandaloneBundle.php b/src/Sculpin/Bundle/StandaloneBundle/SculpinStandaloneBundle.php
index a56a9b91..d1bd8ca4 100644
--- a/src/Sculpin/Bundle/StandaloneBundle/SculpinStandaloneBundle.php
+++ b/src/Sculpin/Bundle/StandaloneBundle/SculpinStandaloneBundle.php
@@ -25,7 +25,7 @@
  */
 class SculpinStandaloneBundle extends Bundle
 {
-    public function build(ContainerBuilder $container)
+    public function build(ContainerBuilder $container): void
     {
         $container->addCompilerPass(new RegisterListenersPass, PassConfig::TYPE_AFTER_REMOVING);
     }
diff --git a/src/Sculpin/Bundle/TextileBundle/DependencyInjection/Configuration.php b/src/Sculpin/Bundle/TextileBundle/DependencyInjection/Configuration.php
index 29a6f98b..e8f8d1f1 100644
--- a/src/Sculpin/Bundle/TextileBundle/DependencyInjection/Configuration.php
+++ b/src/Sculpin/Bundle/TextileBundle/DependencyInjection/Configuration.php
@@ -26,7 +26,7 @@ class Configuration implements ConfigurationInterface
     /**
     * {@inheritdoc}
     */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder;
 
diff --git a/src/Sculpin/Bundle/TextileBundle/DependencyInjection/SculpinTextileExtension.php b/src/Sculpin/Bundle/TextileBundle/DependencyInjection/SculpinTextileExtension.php
index ef6cee6f..b459562b 100644
--- a/src/Sculpin/Bundle/TextileBundle/DependencyInjection/SculpinTextileExtension.php
+++ b/src/Sculpin/Bundle/TextileBundle/DependencyInjection/SculpinTextileExtension.php
@@ -28,7 +28,7 @@ class SculpinTextileExtension extends Extension
     /**
      * {@inheritdoc}
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $configuration = new Configuration;
         $config = $this->processConfiguration($configuration, $configs);
diff --git a/src/Sculpin/Bundle/TextileBundle/SculpinTextileBundle.php b/src/Sculpin/Bundle/TextileBundle/SculpinTextileBundle.php
index 99ec897a..e00add65 100644
--- a/src/Sculpin/Bundle/TextileBundle/SculpinTextileBundle.php
+++ b/src/Sculpin/Bundle/TextileBundle/SculpinTextileBundle.php
@@ -22,5 +22,5 @@
  */
 class SculpinTextileBundle extends Bundle
 {
-    const CONVERTER_NAME = 'textile';
+    public const CONVERTER_NAME = 'textile';
 }
diff --git a/src/Sculpin/Bundle/TextileBundle/TextileConverter.php b/src/Sculpin/Bundle/TextileBundle/TextileConverter.php
index 76983bd0..ad796c9a 100644
--- a/src/Sculpin/Bundle/TextileBundle/TextileConverter.php
+++ b/src/Sculpin/Bundle/TextileBundle/TextileConverter.php
@@ -18,6 +18,7 @@
 use Sculpin\Core\Converter\ConverterInterface;
 use Sculpin\Core\Event\SourceSetEvent;
 use Sculpin\Core\Sculpin;
+use Sculpin\Core\Source\SourceInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
 /**
@@ -64,7 +65,7 @@ public function convert(ConverterContextInterface $converterContext): void
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             Sculpin::EVENT_BEFORE_RUN => 'beforeRun',
@@ -76,8 +77,9 @@ public static function getSubscribedEvents()
      *
      * @param SourceSetEvent $sourceSetEvent Source Set Event
      */
-    public function beforeRun(SourceSetEvent $sourceSetEvent)
+    public function beforeRun(SourceSetEvent $sourceSetEvent): void
     {
+        /** @var SourceInterface $source */
         foreach ($sourceSetEvent->updatedSources() as $source) {
             foreach ($this->extensions as $extension) {
                 if (fnmatch("*.{$extension}", $source->filename())) {
diff --git a/src/Sculpin/Bundle/ThemeBundle/Command/ListCommand.php b/src/Sculpin/Bundle/ThemeBundle/Command/ListCommand.php
index a629d3d1..15ea272d 100644
--- a/src/Sculpin/Bundle/ThemeBundle/Command/ListCommand.php
+++ b/src/Sculpin/Bundle/ThemeBundle/Command/ListCommand.php
@@ -42,7 +42,7 @@ protected function configure()
     /**
      * {@inheritdoc}
      */
-    protected function execute(InputInterface $input, OutputInterface $output)
+    protected function execute(InputInterface $input, OutputInterface $output): void
     {
         $themeRegistry = $this->getContainer()->get('sculpin_theme.theme_registry');
         $activeTheme = $themeRegistry->findActiveTheme();
diff --git a/src/Sculpin/Bundle/ThemeBundle/DependencyInjection/Configuration.php b/src/Sculpin/Bundle/ThemeBundle/DependencyInjection/Configuration.php
index 14f82279..83de4358 100644
--- a/src/Sculpin/Bundle/ThemeBundle/DependencyInjection/Configuration.php
+++ b/src/Sculpin/Bundle/ThemeBundle/DependencyInjection/Configuration.php
@@ -26,7 +26,7 @@ class Configuration implements ConfigurationInterface
     /**
     * {@inheritdoc}
     */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder;
 
diff --git a/src/Sculpin/Bundle/ThemeBundle/DependencyInjection/SculpinThemeExtension.php b/src/Sculpin/Bundle/ThemeBundle/DependencyInjection/SculpinThemeExtension.php
index 5702b9e5..b7725c5b 100644
--- a/src/Sculpin/Bundle/ThemeBundle/DependencyInjection/SculpinThemeExtension.php
+++ b/src/Sculpin/Bundle/ThemeBundle/DependencyInjection/SculpinThemeExtension.php
@@ -28,7 +28,7 @@ class SculpinThemeExtension extends Extension
     /**
      * {@inheritdoc}
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $configuration = new Configuration;
         $config = $this->processConfiguration($configuration, $configs);
diff --git a/src/Sculpin/Bundle/ThemeBundle/ThemeRegistry.php b/src/Sculpin/Bundle/ThemeBundle/ThemeRegistry.php
index 3298b0e5..f4998844 100644
--- a/src/Sculpin/Bundle/ThemeBundle/ThemeRegistry.php
+++ b/src/Sculpin/Bundle/ThemeBundle/ThemeRegistry.php
@@ -13,7 +13,6 @@
 
 namespace Sculpin\Bundle\ThemeBundle;
 
-use Dflydev\Symfony\FinderFactory\FinderFactoryInterface;
 use Symfony\Component\Finder\Finder;
 use Symfony\Component\Yaml\Yaml;
 
@@ -23,14 +22,14 @@ class ThemeRegistry
     private $directory;
     private $activeTheme;
 
-    public function __construct($finderFactory, $directory, $activeTheme = null)
+    public function __construct($finderFactory, string $directory, ?string $activeTheme = null)
     {
         $this->finderFactory = $finderFactory;
         $this->directory = $directory;
         $this->activeTheme = $activeTheme;
     }
 
-    public function listThemes()
+    public function listThemes(): array
     {
         if (! file_exists($this->directory)) {
             return [];
@@ -44,6 +43,7 @@ public function listThemes()
 
         $themes = [];
 
+        /** @var \SplFileInfo $directory */
         foreach ($directories as $directory) {
             $name = basename(dirname($directory->getRealPath())).'/'.basename($directory->getRealPath());
             $theme = ['name' => $name, 'path' => $directory];
@@ -56,7 +56,7 @@ public function listThemes()
         return $themes;
     }
 
-    public function findActiveTheme()
+    public function findActiveTheme(): ?array
     {
         $themes = $this->listThemes();
 
@@ -80,5 +80,7 @@ public function findActiveTheme()
 
             return $theme;
         }
+
+        return null;
     }
 }
diff --git a/src/Sculpin/Bundle/ThemeBundle/ThemeTwigExtension.php b/src/Sculpin/Bundle/ThemeBundle/ThemeTwigExtension.php
index eb6d3f0a..21e84ef6 100644
--- a/src/Sculpin/Bundle/ThemeBundle/ThemeTwigExtension.php
+++ b/src/Sculpin/Bundle/ThemeBundle/ThemeTwigExtension.php
@@ -20,7 +20,7 @@ public function __construct(ThemeRegistry $themeRegistry, $sourceDir, $directory
     /**
      * {@inheritdoc}
      */
-    public function getFunctions()
+    public function getFunctions(): array
     {
         return [
             new \Twig_SimpleFunction('theme_path', [$this, 'themePath']),
@@ -32,7 +32,7 @@ public function getFunctions()
     /**
      * {@inheritdoc}
      */
-    public function getName()
+    public function getName(): string
     {
         return 'theme';
     }
@@ -47,7 +47,7 @@ public function getName()
      *
      * @return string
      */
-    public function themePath($resource)
+    public function themePath(string $resource): string
     {
         if (null === $this->theme) {
             return $resource;
@@ -79,7 +79,7 @@ public function themePath($resource)
      *
      * @return bool
      */
-    public function themePathExists($resource)
+    public function themePathExists(string $resource): bool
     {
         if (file_exists($this->sourceDir.'/'.$resource)) {
             return true;
@@ -113,7 +113,7 @@ public function themePathExists($resource)
      *
      * @return array
      */
-    public function themePaths($resource)
+    public function themePaths(string $resource): array
     {
         $paths = [];
 
@@ -140,7 +140,7 @@ public function themePaths($resource)
         return array_reverse($paths);
     }
 
-    private function findThemeResource($theme, $resource)
+    private function findThemeResource(array $theme, string $resource): string
     {
         if (file_exists($theme['path'].'/'.$resource)) {
             return $this->directory.'/'.$theme['name'].'/'.$resource;
diff --git a/src/Sculpin/Bundle/ThemeBundle/ThemeTwigLoader.php b/src/Sculpin/Bundle/ThemeBundle/ThemeTwigLoader.php
index 9056b2ce..0e37c5e7 100644
--- a/src/Sculpin/Bundle/ThemeBundle/ThemeTwigLoader.php
+++ b/src/Sculpin/Bundle/ThemeBundle/ThemeTwigLoader.php
@@ -39,7 +39,7 @@ public function __construct(ThemeRegistry $themeRegistry, array $extensions)
         $this->chainLoader = new \Twig_Loader_Chain($loaders);
     }
 
-    private function findPaths($theme, array $paths = [])
+    private function findPaths(array $theme, array $paths = []): array
     {
         foreach (['_views', '_layouts', '_includes', '_partials'] as $type) {
             if (is_dir($viewPath = $theme['path'].'/'.$type)) {
@@ -61,7 +61,7 @@ public function getSourceContext($name)
     /**
      * {@inheritdoc}
      */
-    public function exists($name)
+    public function exists($name): bool
     {
         return $this->chainLoader->exists($name);
     }
@@ -69,7 +69,7 @@ public function exists($name)
     /**
      * {@inheritdoc}
      */
-    public function getCacheKey($name)
+    public function getCacheKey($name): string
     {
         return $this->chainLoader->getCacheKey($name);
     }
@@ -77,7 +77,7 @@ public function getCacheKey($name)
     /**
      * {@inheritdoc}
      */
-    public function isFresh($name, $time)
+    public function isFresh($name, $time): bool
     {
         return $this->chainLoader->isFresh($name, $time);
     }
diff --git a/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Compiler/TwigEnvironmentPass.php b/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Compiler/TwigEnvironmentPass.php
index e1259564..7cf42ebc 100644
--- a/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Compiler/TwigEnvironmentPass.php
+++ b/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Compiler/TwigEnvironmentPass.php
@@ -28,7 +28,7 @@ class TwigEnvironmentPass implements CompilerPassInterface
     /**
      * {@inheritdoc}
      */
-    public function process(ContainerBuilder $container)
+    public function process(ContainerBuilder $container): void
     {
         if (false === $container->hasDefinition('sculpin_twig.twig')) {
             return;
diff --git a/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Compiler/TwigLoaderPass.php b/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Compiler/TwigLoaderPass.php
index b971841b..0699d3ae 100644
--- a/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Compiler/TwigLoaderPass.php
+++ b/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Compiler/TwigLoaderPass.php
@@ -28,7 +28,7 @@ class TwigLoaderPass implements CompilerPassInterface
     /**
      * {@inheritdoc}
      */
-    public function process(ContainerBuilder $container)
+    public function process(ContainerBuilder $container): void
     {
         if (false === $container->hasDefinition('sculpin_twig.loader')) {
             return;
diff --git a/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Configuration.php b/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Configuration.php
index 2351bfb5..911ae865 100644
--- a/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Configuration.php
+++ b/src/Sculpin/Bundle/TwigBundle/DependencyInjection/Configuration.php
@@ -26,7 +26,7 @@ class Configuration implements ConfigurationInterface
     /**
     * {@inheritdoc}
     */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder;
 
diff --git a/src/Sculpin/Bundle/TwigBundle/DependencyInjection/SculpinTwigExtension.php b/src/Sculpin/Bundle/TwigBundle/DependencyInjection/SculpinTwigExtension.php
index 173acb3a..36b8e24f 100644
--- a/src/Sculpin/Bundle/TwigBundle/DependencyInjection/SculpinTwigExtension.php
+++ b/src/Sculpin/Bundle/TwigBundle/DependencyInjection/SculpinTwigExtension.php
@@ -28,7 +28,7 @@ class SculpinTwigExtension extends Extension
     /**
      * {@inheritdoc}
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $configuration = new Configuration;
         $config = $this->processConfiguration($configuration, $configs);
diff --git a/src/Sculpin/Bundle/TwigBundle/Environment.php b/src/Sculpin/Bundle/TwigBundle/Environment.php
index 05831636..7545592b 100644
--- a/src/Sculpin/Bundle/TwigBundle/Environment.php
+++ b/src/Sculpin/Bundle/TwigBundle/Environment.php
@@ -23,7 +23,7 @@ class Environment extends \Twig_Environment
      *
      * Hacky workaround to expose invalidation.
      */
-    public function invalidateLoadedTemplates()
+    public function invalidateLoadedTemplates(): void
     {
         try {
             $me     = new \ReflectionClass($this);
diff --git a/src/Sculpin/Bundle/TwigBundle/FilesystemLoader.php b/src/Sculpin/Bundle/TwigBundle/FilesystemLoader.php
index 0e794f6d..1d20dd2e 100644
--- a/src/Sculpin/Bundle/TwigBundle/FilesystemLoader.php
+++ b/src/Sculpin/Bundle/TwigBundle/FilesystemLoader.php
@@ -23,7 +23,7 @@ class FilesystemLoader extends \Twig_Loader_Filesystem
     /**
      * {@inheritdoc}
      */
-    public function getCacheKey($name)
+    public function getCacheKey($name): string
     {
         $filename = $this->findTemplate($name);
 
diff --git a/src/Sculpin/Bundle/TwigBundle/FlexibleExtensionFilesystemLoader.php b/src/Sculpin/Bundle/TwigBundle/FlexibleExtensionFilesystemLoader.php
index f87e897e..4f9f9b01 100644
--- a/src/Sculpin/Bundle/TwigBundle/FlexibleExtensionFilesystemLoader.php
+++ b/src/Sculpin/Bundle/TwigBundle/FlexibleExtensionFilesystemLoader.php
@@ -44,7 +44,7 @@ class FlexibleExtensionFilesystemLoader implements \Twig_LoaderInterface, EventS
      * @param string[] $paths
      * @param string[] $extensions
      */
-    public function __construct($sourceDir, array $sourcePaths, array $paths, array $extensions)
+    public function __construct(string $sourceDir, array $sourcePaths, array $paths, array $extensions)
     {
         $mappedSourcePaths = array_map(function ($path) use ($sourceDir) {
             return $sourceDir.'/'.$path;
@@ -68,7 +68,7 @@ public function __construct($sourceDir, array $sourcePaths, array $paths, array
     /**
      * {@inheritdoc}
      */
-    public function getSourceContext($name)
+    public function getSourceContext($name): \Twig_Source
     {
         $this->getCacheKey($name);
 
@@ -122,7 +122,7 @@ public function isFresh($name, $time)
     /**
      * {@inheritdoc}
      */
-    public function exists($name)
+    public function exists($name): bool
     {
         try {
             $this->getCacheKey($name);
@@ -138,14 +138,14 @@ public function exists($name)
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             Sculpin::EVENT_BEFORE_RUN => 'beforeRun',
         ];
     }
 
-    public function beforeRun(SourceSetEvent $sourceSetEvent)
+    public function beforeRun(SourceSetEvent $sourceSetEvent): void
     {
         if ($sourceSetEvent->sourceSet()->newSources()) {
             $this->cachedCacheKey = [];
diff --git a/src/Sculpin/Bundle/TwigBundle/SculpinTwigBundle.php b/src/Sculpin/Bundle/TwigBundle/SculpinTwigBundle.php
index 3492e258..1a41958a 100644
--- a/src/Sculpin/Bundle/TwigBundle/SculpinTwigBundle.php
+++ b/src/Sculpin/Bundle/TwigBundle/SculpinTwigBundle.php
@@ -25,12 +25,12 @@
  */
 class SculpinTwigBundle extends Bundle
 {
-    const FORMATTER_NAME = 'twig';
+    public const FORMATTER_NAME = 'twig';
 
     /**
      * {@inheritdoc}
      */
-    public function build(ContainerBuilder $container)
+    public function build(ContainerBuilder $container): void
     {
         $container->addCompilerPass(new TwigEnvironmentPass);
         $container->addCompilerPass(new TwigLoaderPass);
diff --git a/src/Sculpin/Bundle/TwigBundle/TemplateResetter.php b/src/Sculpin/Bundle/TwigBundle/TemplateResetter.php
index 4b44f22a..31689b5a 100644
--- a/src/Sculpin/Bundle/TwigBundle/TemplateResetter.php
+++ b/src/Sculpin/Bundle/TwigBundle/TemplateResetter.php
@@ -39,7 +39,7 @@ public function __construct(Environment $twig)
     /**
      * {@inheritdoc}
      */
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             Sculpin::EVENT_BEFORE_RUN => 'beforeRun',
@@ -51,7 +51,7 @@ public static function getSubscribedEvents()
      *
      * @param SourceSetEvent $sourceSetEvent Source Set Event
      */
-    public function beforeRun(SourceSetEvent $sourceSetEvent)
+    public function beforeRun(SourceSetEvent $sourceSetEvent): void
     {
         $updated = $sourceSetEvent->updatedSources();
         if ($updated) {
diff --git a/src/Sculpin/Bundle/TwigBundle/TwigFormatter.php b/src/Sculpin/Bundle/TwigBundle/TwigFormatter.php
index c48c41b9..3f3af056 100644
--- a/src/Sculpin/Bundle/TwigBundle/TwigFormatter.php
+++ b/src/Sculpin/Bundle/TwigBundle/TwigFormatter.php
@@ -77,7 +77,7 @@ public function formatBlocks(FormatContext $formatContext): array
         }
     }
 
-    public function findAllBlocks(\Twig_Template $template, array $context)
+    public function findAllBlocks(\Twig_Template $template, array $context): array
     {
         return $template->getBlockNames($context);
     }
diff --git a/src/Sculpin/Core/SiteConfiguration/SiteConfigurationFactory.php b/src/Sculpin/Core/SiteConfiguration/SiteConfigurationFactory.php
index 29ebb7f5..0180ebfe 100644
--- a/src/Sculpin/Core/SiteConfiguration/SiteConfigurationFactory.php
+++ b/src/Sculpin/Core/SiteConfiguration/SiteConfigurationFactory.php
@@ -56,9 +56,9 @@ private function getConfigFile(string $configFile): ConfigurationInterface
     /**
      * Create Site Configuration
      *
-     * @return Configuration
+     * @return ConfigurationInterface
      */
-    public function create(): Configuration
+    public function create(): ConfigurationInterface
     {
         $config = $this->detectConfig();
         $config->set('env', $this->environment);