diff --git a/Command/DebugFlagsCommand.php b/Command/DebugFlagsCommand.php
index f9027b6..56aaf8c 100644
--- a/Command/DebugFlagsCommand.php
+++ b/Command/DebugFlagsCommand.php
@@ -10,24 +10,12 @@
 
 class DebugFlagsCommand extends Command
 {
-    /**
-     * @var Toggle
-     */
-    private $toggle;
-
-    /**
-     * @var Toggle\ConditionBag
-     */
-    private $conditionBag;
-
-    public function __construct(Toggle $toggle, Toggle\ConditionBag $conditionBag)
+    public function __construct(private readonly Toggle $toggle, private readonly Toggle\ConditionBag $conditionBag)
     {
         parent::__construct();
-        $this->toggle = $toggle;
-        $this->conditionBag = $conditionBag;
     }
 
-    protected function configure()
+    protected function configure(): void
     {
         $this
             ->setName('dzunke:feature_flags:debug')
@@ -50,7 +38,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
         $table->setStyle('borderless');
         $table->setHeaders(['name', 'class']);
         foreach ($this->conditionBag as $name => $condition) {
-            $table->addRow([$name, get_class($condition)]);
+            $table->addRow([$name, $condition::class]);
         }
         $table->render();
 
@@ -67,7 +55,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
         return 0;
     }
 
-    private function renderFlagsTable(OutputInterface $output)
+    private function renderFlagsTable(OutputInterface $output): void
     {
         $flags = $this->toggle->getFlags();
         if (empty($flags)) {
diff --git a/Context.php b/Context.php
index a20947f..5c0ebce 100644
--- a/Context.php
+++ b/Context.php
@@ -15,7 +15,7 @@ class Context
      * @param mixed  $value
      * @return $this
      */
-    public function set($name, $value)
+    public function set($name, $value): self
     {
         $this->context[(string)$name] = $value;
 
@@ -34,7 +34,7 @@ public function get($name)
     /**
      * @return array
      */
-    public function all()
+    public function all(): array
     {
         return $this->context;
     }
@@ -42,7 +42,7 @@ public function all()
     /**
      * @return $this
      */
-    public function clear()
+    public function clear(): self
     {
         $this->context = [];
 
diff --git a/DZunkeFeatureFlagsBundle.php b/DZunkeFeatureFlagsBundle.php
index f2f5a29..1236fe8 100644
--- a/DZunkeFeatureFlagsBundle.php
+++ b/DZunkeFeatureFlagsBundle.php
@@ -9,7 +9,7 @@
 class DZunkeFeatureFlagsBundle extends Bundle
 {
 
-    public function build(ContainerBuilder $container)
+    public function build(ContainerBuilder $container): void
     {
         parent::build($container);
 
diff --git a/DependencyInjection/Compiler/Conditions.php b/DependencyInjection/Compiler/Conditions.php
index 119826a..4b7defa 100644
--- a/DependencyInjection/Compiler/Conditions.php
+++ b/DependencyInjection/Compiler/Conditions.php
@@ -13,7 +13,7 @@ class Conditions implements CompilerPassInterface
     /**
      * @param ContainerBuilder $container
      */
-    public function process(ContainerBuilder $container)
+    public function process(ContainerBuilder $container): void
     {
         if (true !== $container->getParameterBag()->has('d_zunke_feature_flags.config')) {
             throw new \RuntimeException('No parameters with name \'d_zunke_feature_flags.config\' could be found');
@@ -28,7 +28,7 @@ public function process(ContainerBuilder $container)
      * @param array $config
      * @param ContainerBuilder $container
      */
-    private function configureToggle(array $config, ContainerBuilder $container)
+    private function configureToggle(array $config, ContainerBuilder $container): void
     {
         $definition = $container->getDefinition('dz.feature_flags.toggle');
         $definition->addMethodCall('setDefaultState', [$config['default']]);
@@ -52,7 +52,7 @@ private function configureToggle(array $config, ContainerBuilder $container)
     /**
      * @param ContainerBuilder $container
      */
-    private function fillConditionsBag(ContainerBuilder $container)
+    private function fillConditionsBag(ContainerBuilder $container): void
     {
         $taggedConditions = $container->findTaggedServiceIds('dz.feature_flags.toggle.condition');
 
@@ -76,7 +76,7 @@ private function fillConditionsBag(ContainerBuilder $container)
      *
      * @return Definition
      */
-    private function createFlagDefinition($name, Reference $reference, $default)
+    private function createFlagDefinition($name, Reference $reference, $default): Definition
     {
         return new Definition(
             Flag::class,
@@ -92,7 +92,7 @@ private function createFlagDefinition($name, Reference $reference, $default)
      * @param Definition $flag
      * @param array $config
      */
-    private function processFlagConditions(Definition $flag, array $config)
+    private function processFlagConditions(Definition $flag, array $config): void
     {
         foreach($config as $condition => $optionalValues) {
             $flag->addMethodCall(
diff --git a/DependencyInjection/Configuration.php b/DependencyInjection/Configuration.php
index c0b1654..47f1f0f 100644
--- a/DependencyInjection/Configuration.php
+++ b/DependencyInjection/Configuration.php
@@ -3,6 +3,7 @@
 namespace DZunke\FeatureFlagsBundle\DependencyInjection;
 
 use Symfony\Component\Config\Definition\Builder\ArrayNodeDefinition;
+use Symfony\Component\Config\Definition\Builder\NodeDefinition;
 use Symfony\Component\Config\Definition\Builder\TreeBuilder;
 use Symfony\Component\Config\Definition\ConfigurationInterface;
 
@@ -12,7 +13,7 @@ class Configuration implements ConfigurationInterface
     /**
      * @return TreeBuilder
      */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder('d_zunke_feature_flags');
         $rootNode    = $treeBuilder->getRootNode();
@@ -30,9 +31,9 @@ public function getConfigTreeBuilder()
     }
 
     /**
-     * @return ArrayNodeDefinition|\Symfony\Component\Config\Definition\Builder\NodeDefinition
+     * @return ArrayNodeDefinition|NodeDefinition
      */
-    private function addFlags()
+    private function addFlags(): ArrayNodeDefinition|NodeDefinition
     {
         $treeBuilder = new TreeBuilder('flags');
         $node        = $treeBuilder->getRootNode();
diff --git a/DependencyInjection/DZunkeFeatureFlagsExtension.php b/DependencyInjection/DZunkeFeatureFlagsExtension.php
index 1a9457e..3e27175 100644
--- a/DependencyInjection/DZunkeFeatureFlagsExtension.php
+++ b/DependencyInjection/DZunkeFeatureFlagsExtension.php
@@ -14,7 +14,7 @@ class DZunkeFeatureFlagsExtension extends Extension
      * @param array $configs
      * @param ContainerBuilder $container
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $configuration = $this->getConfiguration($configs, $container);
         $config        = $this->processConfiguration($configuration, $configs);
diff --git a/EventListener/ContextCreator.php b/EventListener/ContextCreator.php
index 9b1a788..8a6bef4 100644
--- a/EventListener/ContextCreator.php
+++ b/EventListener/ContextCreator.php
@@ -7,26 +7,19 @@
 
 class ContextCreator
 {
-    /**
-     * @var Context
-     */
-    private $context;
-
     /**
      * @param Context $context
      */
-    public function __construct(Context $context)
+    public function __construct(private readonly Context $context)
     {
-        $this->context = $context;
     }
 
     /**
      * @param RequestEvent $event
      */
-    public function onKernelRequest(RequestEvent $event)
+    public function onKernelRequest(RequestEvent $event): void
     {
         $this->context->set('client_ip', $event->getRequest()->getClientIp());
         $this->context->set('hostname', $event->getRequest()->getHost());
     }
-
 }
diff --git a/Tests/ContextTest.php b/Tests/ContextTest.php
index 3f321fd..a1132f6 100644
--- a/Tests/ContextTest.php
+++ b/Tests/ContextTest.php
@@ -8,7 +8,7 @@
 class ContextTest extends TestCase
 {
 
-    public function testGetAndSet()
+    public function testGetAndSet(): void
     {
         $sut = new Context();
 
@@ -16,7 +16,7 @@ public function testGetAndSet()
         $this->assertSame('value', $sut->get('first'));
     }
 
-    public function testAll()
+    public function testAll(): void
     {
         $sut = new Context();
         $sut->set('first', 'value');
@@ -25,7 +25,7 @@ public function testAll()
         $this->assertSame(1, count($sut->all()));
     }
 
-    public function testClear()
+    public function testClear(): void
     {
         $sut = new Context();
         $sut->set('first', 'value');
@@ -36,4 +36,4 @@ public function testClear()
         $this->assertNull($sut->get('second'));
     }
 
-}
\ No newline at end of file
+}
diff --git a/Tests/DependencyInjection/ConfigurationTest.php b/Tests/DependencyInjection/ConfigurationTest.php
index a53d01e..185a5cb 100644
--- a/Tests/DependencyInjection/ConfigurationTest.php
+++ b/Tests/DependencyInjection/ConfigurationTest.php
@@ -8,7 +8,7 @@
 
 final class ConfigurationTest extends TestCase
 {
-    public function testDefaultConfigurationCouldBeLoaded()
+    public function testDefaultConfigurationCouldBeLoaded(): void
     {
         $container = new ContainerBuilder();
         $extension = new DZunkeFeatureFlagsExtension();
@@ -21,4 +21,4 @@ public function testDefaultConfigurationCouldBeLoaded()
             $config
         );
     }
-}
\ No newline at end of file
+}
diff --git a/Tests/Toggle/ConditionBagTest.php b/Tests/Toggle/ConditionBagTest.php
index f9d64e3..68d684d 100644
--- a/Tests/Toggle/ConditionBagTest.php
+++ b/Tests/Toggle/ConditionBagTest.php
@@ -12,14 +12,14 @@
 class ConditionBagTest extends TestCase
 {
 
-    public function testItImplementsClasses()
+    public function testItImplementsClasses(): void
     {
         $sut = new ConditionBag();
         $this->assertInstanceOf(IteratorAggregate::class, $sut);
         $this->assertInstanceOf(Countable::class, $sut);
     }
 
-    public function testConditionBag()
+    public function testConditionBag(): void
     {
         $conditionMock = $this->createMock(ConditionInterface::class);
         $conditionMock->method('__toString')->willReturn('test_condition');
@@ -39,4 +39,4 @@ public function testConditionBag()
         $this->assertCount(0, $sut->remove('test_condition'));
     }
 
-}
\ No newline at end of file
+}
diff --git a/Tests/Toggle/Conditions/DateTest.php b/Tests/Toggle/Conditions/DateTest.php
index a7233cc..c9aa953 100644
--- a/Tests/Toggle/Conditions/DateTest.php
+++ b/Tests/Toggle/Conditions/DateTest.php
@@ -14,34 +14,34 @@ class DateTest extends TestCase
     /**
      * @var string
      */
-    const CURRENT_DATE = "2016-09-02T00:00:00Z";
+    public const CURRENT_DATE = "2016-09-02T00:00:00Z";
 
     /**
      * @var string
      */
-    const FUTURE_DATE1 = "2020-12-25T12:00:00Z";
+    public const FUTURE_DATE1 = "2020-12-25T12:00:00Z";
 
     /**
      * @var string
      */
-    const FUTURE_DATE2 = "2017-0-0T00:00:00Z";
+    public const FUTURE_DATE2 = "2017-0-0T00:00:00Z";
 
     /**
      * @var string
      */
-    const PAST_DATE1 = "1970-01-01T00:00:00Z";
+    public const PAST_DATE1 = "1970-01-01T00:00:00Z";
 
     /**
      * @var string
      */
-    const PAST_DATE2 = "2014-01-01T00:00:00Z";
+    public const PAST_DATE2 = "2014-01-01T00:00:00Z";
 
     /**
      * Returns an instance of Date with a known "current" date.
      *
      * @return Date
      */
-    public function getInstanceOfDate()
+    public function getInstanceOfDate(): Date
     {
         $contextMock = $this->createMock(Context::class);
 
@@ -56,7 +56,7 @@ public function getInstanceOfDate()
         return $date;
     }
 
-    public function testItExtendsCorrectly()
+    public function testItExtendsCorrectly(): void
     {
         $sut = $this->getInstanceOfDate();
 
@@ -64,14 +64,14 @@ public function testItExtendsCorrectly()
         $this->assertInstanceOf(ConditionInterface::class, $sut);
     }
 
-    public function testItReturnsTrueWithoutStartOrEndDate()
+    public function testItReturnsTrueWithoutStartOrEndDate(): void
     {
         $config = [];
         $sut = $this->getInstanceOfDate();
         $this->assertTrue($sut->validate($config));
     }
 
-    public function testItReturnsTrueWithPastStartDate()
+    public function testItReturnsTrueWithPastStartDate(): void
     {
         $sut = $this->getInstanceOfDate();
         $this->assertTrue($sut->validate([
@@ -88,7 +88,7 @@ public function testItReturnsTrueWithPastStartDate()
         ]));
     }
 
-    public function testItReturnsTrueWithFutureEndDate()
+    public function testItReturnsTrueWithFutureEndDate(): void
     {
         $sut = $this->getInstanceOfDate();
         $this->assertTrue($sut->validate([
@@ -105,7 +105,7 @@ public function testItReturnsTrueWithFutureEndDate()
         ]));
     }
 
-    public function testItReturnsTrueWhenBetweenPastStartAndFutureEndDate()
+    public function testItReturnsTrueWhenBetweenPastStartAndFutureEndDate(): void
     {
         $sut = $this->getInstanceOfDate();
         $this->assertTrue($sut->validate([
@@ -126,7 +126,7 @@ public function testItReturnsTrueWhenBetweenPastStartAndFutureEndDate()
         ]));
     }
 
-    public function testToString()
+    public function testToString(): void
     {
         $sut = $this->getInstanceOfDate();
 
diff --git a/Tests/Toggle/Conditions/DeviceTest.php b/Tests/Toggle/Conditions/DeviceTest.php
index 1315fc9..e22f714 100644
--- a/Tests/Toggle/Conditions/DeviceTest.php
+++ b/Tests/Toggle/Conditions/DeviceTest.php
@@ -32,7 +32,7 @@ public function setUp() : void
         }
     }
 
-    public function testItExtendsCorrectly()
+    public function testItExtendsCorrectly(): void
     {
         $sut = new Device($this->requestStackMock);
 
@@ -40,14 +40,14 @@ public function testItExtendsCorrectly()
         $this->assertInstanceOf(ConditionInterface::class, $sut);
     }
 
-    public function testIsReturnsFalseItConfigIsIncorrect()
+    public function testIsReturnsFalseItConfigIsIncorrect(): void
     {
         $sut = new Device($this->requestStackMock);
 
         $this->assertFalse($sut->validate(null));
     }
 
-    public function testItReturnsFalseIfUserAgentDoesNotExistInArray()
+    public function testItReturnsFalseIfUserAgentDoesNotExistInArray(): void
     {
         $headerBagMock = $this->createMock(HeaderBag::class);
         $headerBagMock->method('get')->with('User-Agent')->willReturn('Custom-User-Agent');
@@ -62,7 +62,7 @@ public function testItReturnsFalseIfUserAgentDoesNotExistInArray()
         $this->assertFalse($sut->validate([], null));
     }
 
-    public function testItReturnsBoolWhenCallingValidateWithoutArgument()
+    public function testItReturnsBoolWhenCallingValidateWithoutArgument(): void
     {
         $headerBagMock = $this->createMock(HeaderBag::class);
         $headerBagMock->method('get')->with('User-Agent')->will($this->onConsecutiveCalls('Matched-User-Agent', 'Random-User-Agent'));
@@ -83,7 +83,7 @@ public function testItReturnsBoolWhenCallingValidateWithoutArgument()
         $this->assertFalse($sut->validate($array, null));
     }
 
-    public function testItReturnsBoolWhenCallingValidateWithArgument()
+    public function testItReturnsBoolWhenCallingValidateWithArgument(): void
     {
         $headerBagMock = $this->createMock(HeaderBag::class);
         $headerBagMock->method('get')->with('User-Agent')->willReturn('Custom-Agent-3', 'Random-User-Agent');
@@ -104,7 +104,7 @@ public function testItReturnsBoolWhenCallingValidateWithArgument()
         $this->assertFalse($sut->validate($array, 'second-agents'));
     }
 
-    public function testToString()
+    public function testToString(): void
     {
         $sut = new Device($this->requestStackMock);
 
diff --git a/Tests/Toggle/Conditions/HostnameTest.php b/Tests/Toggle/Conditions/HostnameTest.php
index 9e001d8..1eb7c70 100644
--- a/Tests/Toggle/Conditions/HostnameTest.php
+++ b/Tests/Toggle/Conditions/HostnameTest.php
@@ -11,7 +11,7 @@
 class HostnameTest extends TestCase
 {
 
-    public function testItExtendsCorrectly()
+    public function testItExtendsCorrectly(): void
     {
         $sut = new Hostname();
 
@@ -19,7 +19,7 @@ public function testItExtendsCorrectly()
         $this->assertInstanceOf(ConditionInterface::class, $sut);
     }
 
-    public function testItReturnsBoolean()
+    public function testItReturnsBoolean(): void
     {
         $contextMock = $this->createMock(Context::class);
         $contextMock->method('get')->will($this->onConsecutiveCalls('myhostname', 'thirdhostname'));
@@ -37,7 +37,7 @@ public function testItReturnsBoolean()
         $this->assertTrue($sut->validate($array));
     }
 
-    public function testToString()
+    public function testToString(): void
     {
         $sut = new Hostname();
 
diff --git a/Tests/Toggle/Conditions/IpAddressTest.php b/Tests/Toggle/Conditions/IpAddressTest.php
index 5412b20..3405eeb 100644
--- a/Tests/Toggle/Conditions/IpAddressTest.php
+++ b/Tests/Toggle/Conditions/IpAddressTest.php
@@ -11,7 +11,7 @@
 class IpAddressTest extends TestCase
 {
 
-    public function testItExtendsCorrectly()
+    public function testItExtendsCorrectly(): void
     {
         $sut = new IpAddress();
 
@@ -19,7 +19,7 @@ public function testItExtendsCorrectly()
         $this->assertInstanceOf(ConditionInterface::class, $sut);
     }
 
-    public function testItReturnsTrue()
+    public function testItReturnsTrue(): void
     {
         $contextMock = $this->createMock(Context::class);
         $contextMock->method('get')->will($this->onConsecutiveCalls('127.0.0.1', '169.168.1.12'));
@@ -38,7 +38,7 @@ public function testItReturnsTrue()
         $this->assertFalse($sut->validate($array));
     }
 
-    public function testToString()
+    public function testToString(): void
     {
         $sut = new IpAddress();
 
diff --git a/Tests/Toggle/Conditions/PercentageTest.php b/Tests/Toggle/Conditions/PercentageTest.php
index 6753712..3faeca9 100644
--- a/Tests/Toggle/Conditions/PercentageTest.php
+++ b/Tests/Toggle/Conditions/PercentageTest.php
@@ -26,7 +26,7 @@ public function setUp() : void
 
     }
 
-    public function testItExtendsCorrectly()
+    public function testItExtendsCorrectly(): void
     {
         $sut = new Percentage($this->requestStackMock);
 
@@ -34,7 +34,7 @@ public function testItExtendsCorrectly()
         $this->assertInstanceOf(ConditionInterface::class, $sut);
     }
 
-    public function testItThrowsExceptionWhenPercentageIsNotSet()
+    public function testItThrowsExceptionWhenPercentageIsNotSet(): void
     {
         $this->expectException(Exception::class);
 
@@ -42,7 +42,7 @@ public function testItThrowsExceptionWhenPercentageIsNotSet()
         $sut->validate([], 'nothing');
     }
 
-    public function testItReturnsTrueWhenCookieIsAlreadySet()
+    public function testItReturnsTrueWhenCookieIsAlreadySet(): void
     {
         $parameterBagMock = $this->createMock(ParameterBag::class);
         $parameterBagMock->method('has')->willReturn(true);
@@ -60,7 +60,7 @@ public function testItReturnsTrueWhenCookieIsAlreadySet()
         ]));
     }
 
-    public function testItReturnsBoolWhenCookieIsNotSet()
+    public function testItReturnsBoolWhenCookieIsNotSet(): void
     {
         $parameterBagMock = $this->createMock(ParameterBag::class);
         $parameterBagMock->method('has')->willReturn(true);
@@ -75,7 +75,7 @@ public function testItReturnsBoolWhenCookieIsNotSet()
         self::assertIsBool($sut->validate(['percentage' => 3]));
     }
 
-    public function testToString()
+    public function testToString(): void
     {
         $sut = new Percentage($this->requestStackMock);
 
diff --git a/Tests/Toggle/FlagTest.php b/Tests/Toggle/FlagTest.php
index 5c08f89..a05aeb6 100644
--- a/Tests/Toggle/FlagTest.php
+++ b/Tests/Toggle/FlagTest.php
@@ -11,7 +11,7 @@
 class FlagTest extends TestCase
 {
 
-    public function testIsActiveReturnsBool()
+    public function testIsActiveReturnsBool(): void
     {
         $conditionBagMock = $this->createMock(ConditionBag::class);
 
@@ -31,7 +31,7 @@ public function testIsActiveReturnsBool()
         $this->assertFalse($sut->isActive());
     }
 
-    public function testIsActiveReturnsDefaultIfEmptyArray()
+    public function testIsActiveReturnsDefaultIfEmptyArray(): void
     {
         $conditionBagMock = $this->createMock(ConditionBag::class);
 
@@ -40,7 +40,7 @@ public function testIsActiveReturnsDefaultIfEmptyArray()
         $this->assertTrue($sut->isActive('argument'));
     }
 
-    public function testGetConfigReturnsArray()
+    public function testGetConfigReturnsArray(): void
     {
         $conditionBagMock = $this->createMock(ConditionBag::class);
 
@@ -49,7 +49,7 @@ public function testGetConfigReturnsArray()
         self::assertIsArray($sut->getConfig());
     }
 
-    public function testAddConditionThrowsException()
+    public function testAddConditionThrowsException(): void
     {
         $this->expectException(InvalidArgumentException::class);
 
@@ -63,7 +63,7 @@ public function testAddConditionThrowsException()
         $this->assertInstanceOf(Flag::class, $return);
     }
 
-    public function testToString()
+    public function testToString(): void
     {
         $conditionBagMock = $this->createMock(ConditionBag::class);
 
@@ -72,4 +72,4 @@ public function testToString()
         $this->assertSame('MySpecialFeature', (string) $sut);
     }
 
-}
\ No newline at end of file
+}
diff --git a/Tests/ToggleTest.php b/Tests/ToggleTest.php
index e85310b..2419861 100644
--- a/Tests/ToggleTest.php
+++ b/Tests/ToggleTest.php
@@ -8,14 +8,14 @@
 class ToggleTest extends TestCase
 {
 
-    public function testDefaultStateIsTrue()
+    public function testDefaultStateIsTrue(): void
     {
         $sut = new Toggle();
 
         $this->assertTrue($sut->isActive('test'));
     }
 
-    public function testDefaultState()
+    public function testDefaultState(): void
     {
         $sut = new Toggle();
 
@@ -23,7 +23,7 @@ public function testDefaultState()
         $this->assertInstanceOf(Toggle::class, $sut->setDefaultState(false));
     }
 
-    public function testGetAndAddFlag()
+    public function testGetAndAddFlag(): void
     {
         $flagMock = self::createMock(Toggle\Flag::class);
         $flagMock->method('__toString')->willReturn('test_flag');
@@ -35,7 +35,7 @@ public function testGetAndAddFlag()
         $this->assertSame($flagMock, $sut->getFlag('test_flag'));
     }
 
-    public function testIsActive()
+    public function testIsActive(): void
     {
         $flagMock = $this->createMock(Toggle\Flag::class);
         $flagMock->method('__toString')->willReturn('MySpecialFeature');
@@ -47,4 +47,4 @@ public function testIsActive()
         $this->assertTrue($sut->isActive('MySpecialFeature'));
         $this->assertFalse($sut->isActive('MySpecialFeature'));
     }
-}
\ No newline at end of file
+}
diff --git a/Tests/Twig/FeatureExtensionTest.php b/Tests/Twig/FeatureExtensionTest.php
index 076ed89..9af4c90 100644
--- a/Tests/Twig/FeatureExtensionTest.php
+++ b/Tests/Twig/FeatureExtensionTest.php
@@ -10,7 +10,7 @@
 class FeatureExtensionTest extends TestCase
 {
 
-    public function testGetFunctions()
+    public function testGetFunctions(): void
     {
         $toggleMock = $this->createMock(Toggle::class);
 
@@ -21,7 +21,7 @@ public function testGetFunctions()
         $this->assertInstanceOf(TwigFunction::class, reset($functions));
     }
 
-    public function testGetName()
+    public function testGetName(): void
     {
         $toggleMock = $this->createMock(Toggle::class);
 
@@ -30,4 +30,4 @@ public function testGetName()
         $this->assertSame('d_zunke_feature_extension', $sut->getName());
     }
 
-}
\ No newline at end of file
+}
diff --git a/Toggle.php b/Toggle.php
index 218b260..89788c2 100644
--- a/Toggle.php
+++ b/Toggle.php
@@ -21,7 +21,7 @@ class Toggle
      * @param bool $defaultState
      * @return $this
      */
-    public function setDefaultState($defaultState)
+    public function setDefaultState($defaultState): self
     {
         $this->defaultState = (bool)$defaultState;
 
@@ -32,7 +32,7 @@ public function setDefaultState($defaultState)
      * @param Flag $flag
      * @return $this
      */
-    public function addFlag(Flag $flag)
+    public function addFlag(Flag $flag): self
     {
         $this->flags[(string)$flag] = $flag;
 
@@ -43,7 +43,7 @@ public function addFlag(Flag $flag)
      * @param $name
      * @return Flag|null
      */
-    public function getFlag($name)
+    public function getFlag($name): ?Flag
     {
         if (isset($this->flags[$name])) {
             return $this->flags[$name];
@@ -55,7 +55,7 @@ public function getFlag($name)
     /**
      * @return Toggle\Flag[]
      */
-    public function getFlags()
+    public function getFlags(): array
     {
         return $this->flags;
     }
@@ -65,7 +65,7 @@ public function getFlags()
      * @param array  $arguments
      * @return bool
      */
-    public function isActive($flag, $arguments = null)
+    public function isActive($flag, $arguments = null): bool
     {
         if (!isset($this->flags[$flag])) {
             return $this->defaultState;
diff --git a/Toggle/ConditionBag.php b/Toggle/ConditionBag.php
index 2d29923..a5f8304 100644
--- a/Toggle/ConditionBag.php
+++ b/Toggle/ConditionBag.php
@@ -10,7 +10,7 @@ class ConditionBag implements \IteratorAggregate, \Countable
     /**
      * @var ConditionInterface[]
      */
-    protected $conditions = [];
+    protected array $conditions = [];
 
     /**
      * @return \ArrayIterator
@@ -31,7 +31,7 @@ public function count(): int
     /**
      * @return Conditions\ConditionInterface[]
      */
-    public function all()
+    public function all(): array
     {
         return $this->conditions;
     }
@@ -40,7 +40,7 @@ public function all()
      * @param array $conditions
      * @return $this
      */
-    public function add(array $conditions)
+    public function add(array $conditions): self
     {
         foreach ($conditions as $condition) {
             $this->set((string)$condition, $condition);
@@ -54,7 +54,7 @@ public function add(array $conditions)
      * @param ConditionInterface $condition
      * @return $this
      */
-    public function set($name, ConditionInterface $condition)
+    public function set(string $name, ConditionInterface $condition): self
     {
         $this->conditions[$name] = $condition;
 
@@ -62,18 +62,18 @@ public function set($name, ConditionInterface $condition)
     }
 
     /**
-     * @param $name
+     * @param string $name
      * @return ConditionInterface|null
      */
-    public function get($name)
+    public function get(string $name): ?ConditionInterface
     {
-        return isset($this->conditions[$name]) ? $this->conditions[$name] : null;
+        return $this->conditions[$name] ?? null;
     }
 
     /**
      * @return array
      */
-    public function keys()
+    public function keys(): array
     {
         return array_keys($this->conditions);
     }
@@ -82,7 +82,7 @@ public function keys()
      * @param string $name
      * @return bool
      */
-    public function has($name)
+    public function has(string $name): bool
     {
         return array_key_exists($name, $this->conditions);
     }
@@ -91,7 +91,7 @@ public function has($name)
      * @param string $name
      * @return $this
      */
-    public function remove($name)
+    public function remove(string $name): self
     {
         unset($this->conditions[$name]);
 
diff --git a/Toggle/Conditions/AbstractCondition.php b/Toggle/Conditions/AbstractCondition.php
index a42c8e5..0af556d 100644
--- a/Toggle/Conditions/AbstractCondition.php
+++ b/Toggle/Conditions/AbstractCondition.php
@@ -10,12 +10,12 @@ abstract class AbstractCondition implements ConditionInterface
      * @var Context
      */
     protected $context;
-    
+
     /**
      * @param Context $context
      * @return $this
      */
-    public function setContext(Context $context)
+    public function setContext(Context $context): static
     {
         $this->context = $context;
 
diff --git a/Toggle/Conditions/ConditionInterface.php b/Toggle/Conditions/ConditionInterface.php
index 7433e53..7e1f8b4 100644
--- a/Toggle/Conditions/ConditionInterface.php
+++ b/Toggle/Conditions/ConditionInterface.php
@@ -6,10 +6,10 @@
 
 interface ConditionInterface
 {
-    public function __toString();
+    public function __toString(): string;
 
-    public function setContext(Context $context);
+    public function setContext(Context $context): static;
 
-    public function validate($config, $argument = null);
+    public function validate($config, $argument = null): bool;
 
 }
diff --git a/Toggle/Conditions/Date.php b/Toggle/Conditions/Date.php
index 6edbe41..0243920 100644
--- a/Toggle/Conditions/Date.php
+++ b/Toggle/Conditions/Date.php
@@ -8,7 +8,7 @@ class Date extends AbstractCondition implements ConditionInterface
 {
     /**
      * Current date, in DateTime format.
-     * 
+     *
      * @see http://php.net/manual/en/class.datetime.php
      *
      * @var string
@@ -20,7 +20,7 @@ class Date extends AbstractCondition implements ConditionInterface
      * @param null  $argument
      * @return bool
      */
-    public function validate($config, $argument = null)
+    public function validate($config, $argument = null): bool
     {
         $currentDate = new DateTime($this->currentDate);
         $startDate = !empty($config['start_date']) ? new DateTime($config['start_date']) : $currentDate;
@@ -31,7 +31,7 @@ public function validate($config, $argument = null)
     /**
      * @return string
      */
-    public function __toString()
+    public function __toString(): string
     {
         return 'date';
     }
diff --git a/Toggle/Conditions/Device.php b/Toggle/Conditions/Device.php
index 565b380..a8d6895 100644
--- a/Toggle/Conditions/Device.php
+++ b/Toggle/Conditions/Device.php
@@ -26,7 +26,7 @@ public function __construct(RequestStack $request)
      * @param null  $argument
      * @return bool
      */
-    public function validate($config, $argument = null)
+    public function validate($config, $argument = null): bool
     {
         if (!$this->validateConfig($config)) {
             return false;
@@ -36,22 +36,21 @@ public function validate($config, $argument = null)
 
         if (is_null($argument)) {
             foreach ($config as $name => $regex) {
-                if (preg_match($regex, $userAgent)) {
+                if (preg_match($regex, (string) $userAgent)) {
                     return true;
                 }
             }
         } elseif (!is_null($argument) && array_key_exists($argument, $config)) {
-            return (bool)preg_match($config[$argument], $userAgent);
+            return (bool)preg_match($config[$argument], (string) $userAgent);
         }
 
         return false;
     }
 
     /**
-     * @param mixed $config
      * @return bool
      */
-    private function validateConfig($config)
+    private function validateConfig(mixed $config): bool
     {
         if (!is_array($config)) {
             return false;
@@ -63,7 +62,7 @@ private function validateConfig($config)
     /**
      * @return string
      */
-    public function __toString()
+    public function __toString(): string
     {
         return 'device';
     }
diff --git a/Toggle/Conditions/Hostname.php b/Toggle/Conditions/Hostname.php
index 7eeef66..183f80c 100644
--- a/Toggle/Conditions/Hostname.php
+++ b/Toggle/Conditions/Hostname.php
@@ -10,7 +10,7 @@ class Hostname extends AbstractCondition implements ConditionInterface
      * @param null  $argument
      * @return bool
      */
-    public function validate($config, $argument = null)
+    public function validate($config, $argument = null): bool
     {
         return in_array(
             $this->context->get('hostname'),
@@ -21,7 +21,7 @@ public function validate($config, $argument = null)
     /**
      * @return string
      */
-    public function __toString()
+    public function __toString(): string
     {
         return 'hostname';
     }
diff --git a/Toggle/Conditions/IpAddress.php b/Toggle/Conditions/IpAddress.php
index 3007d01..046ec3a 100644
--- a/Toggle/Conditions/IpAddress.php
+++ b/Toggle/Conditions/IpAddress.php
@@ -10,7 +10,7 @@ class IpAddress extends AbstractCondition implements ConditionInterface
      * @param null  $argument
      * @return bool
      */
-    public function validate($config, $argument = null)
+    public function validate($config, $argument = null): bool
     {
         return in_array(
             $this->context->get('client_ip'),
@@ -21,7 +21,7 @@ public function validate($config, $argument = null)
     /**
      * @return string
      */
-    public function __toString()
+    public function __toString(): string
     {
         return 'ip_address';
     }
diff --git a/Toggle/Conditions/Percentage.php b/Toggle/Conditions/Percentage.php
index f8da3e1..122b82d 100644
--- a/Toggle/Conditions/Percentage.php
+++ b/Toggle/Conditions/Percentage.php
@@ -8,17 +8,14 @@
 class Percentage extends AbstractCondition implements ConditionInterface
 {
 
-    const BASIC_COOKIE_NAME = '84a0b3f187a1d3bfefbb51d4b93074b1e5d9102a';
+    public const BASIC_COOKIE_NAME = '84a0b3f187a1d3bfefbb51d4b93074b1e5d9102a';
 
-    const BASIC_PERCENTAGE = 100;
+    public const BASIC_PERCENTAGE = 100;
 
-    const BASIC_LIFETIME = 86400;
+    public const BASIC_LIFETIME = 86400;
 
-    private RequestStack $requestStack;
-
-    public function __construct(RequestStack $requestStack)
+    public function __construct(private readonly RequestStack $requestStack)
     {
-        $this->requestStack = $requestStack;
     }
 
     /**
@@ -27,7 +24,7 @@ public function __construct(RequestStack $requestStack)
      * @return bool
      * @throws \Exception
      */
-    public function validate($config, $argument = null)
+    public function validate($config, $argument = null): bool
     {
         $config = $this->formatConfig($config);
 
@@ -39,7 +36,7 @@ public function validate($config, $argument = null)
         setcookie(
             $config['cookie'],
             $value,
-            time() + $config['lifetime']
+            ['expires' => time() + $config['lifetime']]
         );
 
         return (bool)$value;
@@ -65,7 +62,7 @@ private function formatConfig($config)
     /**
      * @return int
      */
-    private function generateRandomNumber()
+    private function generateRandomNumber(): int
     {
         return 100 * (mt_rand(0, mt_getrandmax() - 1) / mt_getrandmax());
     }
@@ -73,7 +70,7 @@ private function generateRandomNumber()
     /**
      * @return string
      */
-    public function __toString()
+    public function __toString(): string
     {
         return 'percentage';
     }
diff --git a/Toggle/Flag.php b/Toggle/Flag.php
index fda570e..7c9feda 100644
--- a/Toggle/Flag.php
+++ b/Toggle/Flag.php
@@ -2,23 +2,13 @@
 
 namespace DZunke\FeatureFlagsBundle\Toggle;
 
-class Flag
+class Flag implements \Stringable
 {
-    /**
-     * @var string
-     */
-    private $name;
-
     /**
      * @var bool
      */
     private $active;
 
-    /**
-     * @var ConditionBag
-     */
-    private $conditions;
-
     /**
      * @var array
      */
@@ -28,18 +18,17 @@ class Flag
      * @param              $name
      * @param ConditionBag $conditions
      * @param bool         $defaultState
+     * @param string $name
      */
-    public function __construct($name, ConditionBag $conditions, $defaultState = true)
+    public function __construct(private $name, private readonly ConditionBag $conditions, $defaultState = true)
     {
-        $this->name       = $name;
-        $this->conditions = $conditions;
         $this->active     = (bool)$defaultState;
     }
 
     /**
      * @return string
      */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->name;
     }
@@ -49,7 +38,7 @@ public function __toString()
      * @param $config
      * @return $this
      */
-    public function addCondition($name, $config)
+    public function addCondition($name, $config): self
     {
         if (!$this->conditions->has($name)) {
             throw new \InvalidArgumentException(
@@ -65,7 +54,7 @@ public function addCondition($name, $config)
     /**
      * @return array
      */
-    public function getConfig()
+    public function getConfig(): array
     {
         return $this->config;
     }
@@ -74,7 +63,7 @@ public function getConfig()
      * @param array $arguments
      * @return bool
      */
-    public function isActive($arguments = null)
+    public function isActive($arguments = null): bool
     {
         $actual = $this->active;
 
diff --git a/Twig/FeatureExtension.php b/Twig/FeatureExtension.php
index 92a8994..6a5ef53 100644
--- a/Twig/FeatureExtension.php
+++ b/Twig/FeatureExtension.php
@@ -28,7 +28,7 @@ public function __construct(Toggle $toggle)
     public function getFunctions(): array
     {
         return [
-            new TwigFunction('has_feature', [$this, 'checkFeature'], ['is_safe' => ['html']]),
+            new TwigFunction('has_feature', $this->checkFeature(...), ['is_safe' => ['html']]),
         ];
     }
 
@@ -37,12 +37,12 @@ public function getFunctions(): array
      * @param  array  $arguments
      * @return bool
      */
-    public function checkFeature($name, $arguments = null)
+    public function checkFeature($name, $arguments = null): bool
     {
         return $this->toggle->isActive($name, $arguments);
     }
 
-    public function getName()
+    public function getName(): string
     {
         return 'd_zunke_feature_extension';
     }