diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 0dde6b68..8506ea11 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -28,4 +28,4 @@ jobs:
       os: >-
         ['ubuntu-latest', 'windows-latest']
       php: >-
-        ['7.4', '8.0', '8.1']
+        ['8.0', '8.1']
diff --git a/.github/workflows/rector.yml b/.github/workflows/rector.yml
new file mode 100644
index 00000000..adacd735
--- /dev/null
+++ b/.github/workflows/rector.yml
@@ -0,0 +1,21 @@
+on:
+  pull_request:
+    paths-ignore:
+      - 'docs/**'
+      - 'README.md'
+      - 'CHANGELOG.md'
+      - '.gitignore'
+      - '.gitattributes'
+      - 'infection.json.dist'
+      - 'psalm.xml'
+
+name: rector
+
+jobs:
+  rector:
+    uses: yiisoft/actions/.github/workflows/rector.yml@master
+    with:
+      os: >-
+        ['ubuntu-latest']
+      php: >-
+        ['8.0']
diff --git a/.github/workflows/static.yml b/.github/workflows/static.yml
index 40ac2609..96b26790 100644
--- a/.github/workflows/static.yml
+++ b/.github/workflows/static.yml
@@ -28,4 +28,4 @@ jobs:
       os: >-
         ['ubuntu-latest']
       php: >-
-        ['7.4', '8.0', '8.1']
+        ['8.0', '8.1']
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 613f72f5..383ea0c7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,11 +2,11 @@
 
 ## 1.0.2 under development
 
-- no changes in this release.
+- Enh #162: Raise minimum PHP version to 8.0 and refactor code (@xepozz, @vjik)
 
 ## 1.0.1 June 17, 2022
 
-- Enh #159: Add support for `yiisoft/definitions` version `^2.0` (vjik)
+- Enh #159: Add support for `yiisoft/definitions` version `^2.0` (@vjik)
 
 ## 1.0.0 December 11, 2021
 
diff --git a/README.md b/README.md
index fae67d5c..63859de1 100644
--- a/README.md
+++ b/README.md
@@ -20,14 +20,14 @@ with dependencies resolved by a [PSR-11](https://www.php-fig.org/psr/psr-11/) co
 
 ## Requirements
 
-- PHP 7.4 or higher.
+- PHP 8.0 or higher.
 
 ## Installation
 
 The package could be installed with [composer](http://getcomposer.org/download/):
 
 ```shell
-composer require yiisoft/definitions --prefer-dist
+composer require yiisoft/definitions
 ```
 
 ## General usage
diff --git a/composer.json b/composer.json
index 6805800b..e9ce6704 100644
--- a/composer.json
+++ b/composer.json
@@ -16,12 +16,13 @@
         "source": "https://github.com/yiisoft/factory"
     },
     "require": {
-        "php": "^7.4|^8.0",
+        "php": "^8.0",
         "psr/container": "^1.0|^2.0",
         "yiisoft/definitions": "^1.0|^2.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^9.5",
+        "rector/rector": "^0.14.3",
         "roave/infection-static-analysis-plugin": "^1.16",
         "spatie/phpunit-watcher": "^1.23",
         "vimeo/psalm": "^4.18",
diff --git a/rector.php b/rector.php
new file mode 100644
index 00000000..63713ce9
--- /dev/null
+++ b/rector.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\CodeQuality\Rector\Class_\InlineConstructorDefaultToPropertyRector;
+use Rector\Config\RectorConfig;
+use Rector\Set\ValueObject\LevelSetList;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->paths([
+        __DIR__ . '/src',
+        __DIR__ . '/tests',
+    ]);
+
+    // register a single rule
+    $rectorConfig->rule(InlineConstructorDefaultToPropertyRector::class);
+
+    // define sets of rules
+    $rectorConfig->sets([
+        LevelSetList::UP_TO_PHP_80,
+    ]);
+};
diff --git a/src/Factory.php b/src/Factory.php
index edfea07d..074e7e1d 100644
--- a/src/Factory.php
+++ b/src/Factory.php
@@ -17,26 +17,16 @@
 
 /**
  * Factory allows creating objects passing arguments runtime.
- * A factory will try to use a PSR-11 compliant container to get dependencies,
- * but will fall back to manual instantiation
- * if the container cannot provide a required dependency.
+ * A factory will try to use a PSR-11 compliant container to get dependencies, but will fall back to manual
+ * instantiation if the container cannot provide a required dependency.
  */
 final class Factory
 {
     private FactoryInternalContainer $internalContainer;
 
     /**
-     * @var bool $validate If definitions should be validated when set.
-     */
-    private bool $validate;
-
-    /**
-     * Factory constructor.
-     *
      * @param ContainerInterface $container Container to use for resolving dependencies.
-     * @param array $definitions Definitions to create objects with.
-     * @psalm-param array<string, mixed> $definitions
-     *
+     * @param array<string, mixed> $definitions Definitions to create objects with.
      * @param bool $validate If definitions should be validated when set.
      *
      * @throws InvalidConfigException
@@ -44,20 +34,16 @@ final class Factory
     public function __construct(
         ContainerInterface $container,
         array $definitions = [],
-        bool $validate = true
+        private bool $validate = true
     ) {
-        $this->validate = $validate;
         $this->validateDefinitions($definitions);
         $this->internalContainer = new FactoryInternalContainer($container, $definitions);
     }
 
     /**
-     * @param array $definitions Definitions to create objects with.
-     * @psalm-param array<string, mixed> $definitions
+     * @param array<string, mixed> $definitions Definitions to create objects with.
      *
      * @throws InvalidConfigException
-     *
-     * @return self
      */
     public function withDefinitions(array $definitions): self
     {
@@ -134,7 +120,7 @@ private function validateDefinitions(array $definitions): void
      * @psalm-return ($config is class-string ? T : mixed)
      * @psalm-suppress MixedReturnStatement
      */
-    public function create($config)
+    public function create(mixed $config): mixed
     {
         if ($this->validate) {
             DefinitionValidator::validate($config);
@@ -156,18 +142,17 @@ public function create($config)
     }
 
     /**
-     * @param mixed $config
-     *
      * @throws InvalidConfigException
      */
-    private function createDefinition($config): DefinitionInterface
+    private function createDefinition(mixed $config): DefinitionInterface
     {
         $definition = Normalizer::normalize($config);
 
         if (
-            ($definition instanceof ArrayDefinition) &&
-            $this->internalContainer->hasDefinition($definition->getClass()) &&
-            ($containerDefinition = $this->internalContainer->getDefinition($definition->getClass())) instanceof ArrayDefinition
+            ($definition instanceof ArrayDefinition)
+            && $this->internalContainer->hasDefinition($definition->getClass())
+            && ($containerDefinition = $this->internalContainer->getDefinition($definition->getClass()))
+            instanceof ArrayDefinition
         ) {
             $definition = $this->mergeDefinitions(
                 $containerDefinition,
diff --git a/src/FactoryInternalContainer.php b/src/FactoryInternalContainer.php
index d647cfd4..687f3d46 100644
--- a/src/FactoryInternalContainer.php
+++ b/src/FactoryInternalContainer.php
@@ -27,45 +27,27 @@
 final class FactoryInternalContainer implements ContainerInterface
 {
     /**
-     * @var ContainerInterface Container to use for resolving dependencies.
-     */
-    private ContainerInterface $container;
-
-    /**
-     * @var array Definitions to create objects with.
-     * @psalm-var array<string, mixed>
-     */
-    private array $definitions;
-
-    /**
-     * @var DefinitionInterface[] Object created from definitions indexed by their types.
-     * @psalm-var array<string, DefinitionInterface>
+     * @var array<string, DefinitionInterface> Object created from definitions indexed by their types.
      */
     private array $definitionInstances = [];
 
     /**
-     * @var array Used to collect IDs instantiated during build to detect circular references.
-     *
-     * @psalm-var array<string,1>
+     * @var array<string,1> Used to collect IDs instantiated during build to detect circular references.
      */
     private array $creatingIds = [];
 
     /**
      * @param ContainerInterface $container Container to use for resolving dependencies.
-     * @param array $definitions Definitions to create objects with.
-     * @psalm-param array<string, mixed> $definitions
+     * @param array<string, mixed> $definitions Definitions to create objects with.
      */
-    public function __construct(ContainerInterface $container, array $definitions = [])
-    {
-        $this->container = $container;
-        $this->definitions = $definitions;
+    public function __construct(
+        private ContainerInterface $container,
+        private array $definitions = []
+    ) {
     }
 
     /**
-     * @param array $definitions Definitions to create objects with.
-     * @psalm-param array<string, mixed> $definitions
-     *
-     * @return self
+     * @param array<string, mixed> $definitions Definitions to create objects with.
      */
     public function withDefinitions(array $definitions): self
     {
@@ -80,11 +62,8 @@ public function withDefinitions(array $definitions): self
      * @inheritDoc
      *
      * @param string $id
-     *
-     * @return mixed|object
-     * @psalm-suppress InvalidThrow
      */
-    public function get($id)
+    public function get($id): mixed
     {
         if ($this->hasDefinition($id)) {
             return $this->build($id);
@@ -102,10 +81,7 @@ public function has($id): bool
         return $this->hasDefinition($id) || $this->container->has($id);
     }
 
-    /**
-     * @return mixed
-     */
-    public function create(DefinitionInterface $definition)
+    public function create(DefinitionInterface $definition): mixed
     {
         if ($definition instanceof ArrayDefinition) {
             $this->creatingIds[$definition->getClass()] = 1;
@@ -170,23 +146,21 @@ public function hasDefinition(string $id): bool
     }
 
     /**
-     * @param string $id
-     *
      * @throws CircularReferenceException
      * @throws InvalidConfigException
      * @throws NotFoundException
      * @throws NotInstantiableException
-     *
-     * @return mixed|object
      */
-    private function build(string $id)
+    private function build(string $id): mixed
     {
         if (isset($this->creatingIds[$id])) {
-            throw new CircularReferenceException(sprintf(
-                'Circular reference to "%s" detected while creating: %s.',
-                $id,
-                implode(', ', array_keys($this->creatingIds))
-            ));
+            throw new CircularReferenceException(
+                sprintf(
+                    'Circular reference to "%s" detected while creating: %s.',
+                    $id,
+                    implode(', ', array_keys($this->creatingIds))
+                )
+            );
         }
 
         $definition = $this->getDefinition($id);
diff --git a/src/NotFoundException.php b/src/NotFoundException.php
index bb84e203..3bdb8845 100644
--- a/src/NotFoundException.php
+++ b/src/NotFoundException.php
@@ -12,14 +12,12 @@
  */
 final class NotFoundException extends Exception implements NotFoundExceptionInterface
 {
-    private string $id;
-
     /**
      * @param string $id ID of the definition or name of the class that was not found.
      */
-    public function __construct(string $id)
-    {
-        $this->id = $id;
+    public function __construct(
+        private string $id
+    ) {
         parent::__construct(sprintf('No definition or class found or resolvable for %s.', $id));
     }
 
diff --git a/tests/Support/Car.php b/tests/Support/Car.php
index 3e4bea88..a212d602 100644
--- a/tests/Support/Car.php
+++ b/tests/Support/Car.php
@@ -7,13 +7,9 @@
 final class Car
 {
     public ?ColorInterface $color = null;
-    private EngineInterface $engine;
-    private array $moreEngines;
 
-    public function __construct(EngineInterface $engine, array $moreEngines = [])
+    public function __construct(private EngineInterface $engine, private array $moreEngines = [])
     {
-        $this->engine = $engine;
-        $this->moreEngines = $moreEngines;
     }
 
     public function getEngine(): EngineInterface
diff --git a/tests/Support/Circular/CircularA.php b/tests/Support/Circular/CircularA.php
index d7143b20..06dbdcfd 100644
--- a/tests/Support/Circular/CircularA.php
+++ b/tests/Support/Circular/CircularA.php
@@ -6,10 +6,7 @@
 
 final class CircularA
 {
-    public ?CircularB $b;
-
-    public function __construct(?CircularB $b = null)
+    public function __construct(public ?CircularB $b = null)
     {
-        $this->b = $b;
     }
 }
diff --git a/tests/Support/Circular/CircularB.php b/tests/Support/Circular/CircularB.php
index c96a9bf6..5b2486a7 100644
--- a/tests/Support/Circular/CircularB.php
+++ b/tests/Support/Circular/CircularB.php
@@ -6,10 +6,7 @@
 
 final class CircularB
 {
-    public ?CircularA $a;
-
-    public function __construct(?CircularA $a = null)
+    public function __construct(public ?CircularA $a = null)
     {
-        $this->a = $a;
     }
 }
diff --git a/tests/Support/Cube.php b/tests/Support/Cube.php
index 871a848e..3b3a3f3e 100644
--- a/tests/Support/Cube.php
+++ b/tests/Support/Cube.php
@@ -6,11 +6,8 @@
 
 final class Cube
 {
-    private ColorInterface $color;
-
-    public function __construct(ColorInterface $color)
+    public function __construct(private ColorInterface $color)
     {
-        $this->color = $color;
     }
 
     public function getColor(): ColorInterface
diff --git a/tests/Support/EngineMarkOne.php b/tests/Support/EngineMarkOne.php
index f4311d68..f77bff5c 100644
--- a/tests/Support/EngineMarkOne.php
+++ b/tests/Support/EngineMarkOne.php
@@ -8,11 +8,8 @@ final class EngineMarkOne implements EngineInterface
 {
     public const NAME = 'Mark One';
 
-    private int $number;
-
-    public function __construct(int $number = 0)
+    public function __construct(private int $number = 0)
     {
-        $this->number = $number;
     }
 
     public function getName(): string
diff --git a/tests/Support/ExcessiveConstructorParameters.php b/tests/Support/ExcessiveConstructorParameters.php
index 92b7dd87..0ffc33f8 100644
--- a/tests/Support/ExcessiveConstructorParameters.php
+++ b/tests/Support/ExcessiveConstructorParameters.php
@@ -8,13 +8,10 @@
 
 final class ExcessiveConstructorParameters
 {
-    private $parameter;
-
     private array $allParameters;
 
-    public function __construct($parameter)
+    public function __construct(private $parameter)
     {
-        $this->parameter = $parameter;
         $this->allParameters = func_get_args();
     }
 
diff --git a/tests/Support/Firefighter.php b/tests/Support/Firefighter.php
index 7592bdc8..e579f5cf 100644
--- a/tests/Support/Firefighter.php
+++ b/tests/Support/Firefighter.php
@@ -6,11 +6,8 @@
 
 final class Firefighter
 {
-    private ?string $name;
-
-    public function __construct(?string $name)
+    public function __construct(private ?string $name)
     {
-        $this->name = $name;
     }
 
     public function getName(): ?string
diff --git a/tests/Support/GearBox.php b/tests/Support/GearBox.php
index ac699560..2df8f193 100644
--- a/tests/Support/GearBox.php
+++ b/tests/Support/GearBox.php
@@ -9,10 +9,7 @@
  */
 final class GearBox
 {
-    private int $maxGear;
-
-    public function __construct(int $maxGear = 5)
+    public function __construct(private int $maxGear = 5)
     {
-        $this->maxGear = $maxGear;
     }
 }
diff --git a/tests/Support/MethodTest.php b/tests/Support/MethodTest.php
index 6142b113..a4fdaff3 100644
--- a/tests/Support/MethodTest.php
+++ b/tests/Support/MethodTest.php
@@ -16,10 +16,7 @@ public function getValue()
         return $this->value;
     }
 
-    /**
-     * @param mixed $value
-     */
-    public function setValue($value): void
+    public function setValue(mixed $value): void
     {
         $this->value = $value;
     }
diff --git a/tests/Support/NullableConcreteDependency.php b/tests/Support/NullableConcreteDependency.php
index 91116722..00fd9705 100644
--- a/tests/Support/NullableConcreteDependency.php
+++ b/tests/Support/NullableConcreteDependency.php
@@ -6,11 +6,8 @@
 
 final class NullableConcreteDependency
 {
-    private Car $car;
-
-    public function __construct(?Car $car)
+    public function __construct(private ?Car $car)
     {
-        $this->car = $car;
     }
 
     public function getCar(): Car
diff --git a/tests/Support/NullableInterfaceDependency.php b/tests/Support/NullableInterfaceDependency.php
index 1338359d..98225e8f 100644
--- a/tests/Support/NullableInterfaceDependency.php
+++ b/tests/Support/NullableInterfaceDependency.php
@@ -6,11 +6,8 @@
 
 final class NullableInterfaceDependency
 {
-    private ?EngineInterface $engine;
-
-    public function __construct(?EngineInterface $engine)
+    public function __construct(private ?EngineInterface $engine)
     {
-        $this->engine = $engine;
     }
 
     public function getEngine(): ?EngineInterface
diff --git a/tests/Support/NullableScalarConstructorArgument.php b/tests/Support/NullableScalarConstructorArgument.php
index a4c67495..efe31397 100644
--- a/tests/Support/NullableScalarConstructorArgument.php
+++ b/tests/Support/NullableScalarConstructorArgument.php
@@ -6,11 +6,8 @@
 
 final class NullableScalarConstructorArgument
 {
-    private ?string $name;
-
-    public function __construct(?string $name)
+    public function __construct(private ?string $name)
     {
-        $this->name = $name;
     }
 
     public function getName(): ?string
diff --git a/tests/Support/Phone.php b/tests/Support/Phone.php
index 55ba1007..1f531294 100644
--- a/tests/Support/Phone.php
+++ b/tests/Support/Phone.php
@@ -7,8 +7,6 @@
 final class Phone
 {
     private ?string $id = null;
-    private ?string $name;
-    private ?string $version;
     private array $colors;
     private array $apps = [];
     private ?string $author = null;
@@ -17,10 +15,8 @@ final class Phone
     public bool $dev = false;
     public ?string $codeName = null;
 
-    public function __construct(?string $name = null, ?string $version = null, string ...$colors)
+    public function __construct(private ?string $name = null, private ?string $version = null, string ...$colors)
     {
-        $this->name = $name;
-        $this->version = $version;
         $this->colors = $colors;
     }
 
diff --git a/tests/Support/PinkCircle.php b/tests/Support/PinkCircle.php
index 30e55e6d..4301a6fd 100644
--- a/tests/Support/PinkCircle.php
+++ b/tests/Support/PinkCircle.php
@@ -6,11 +6,8 @@
 
 final class PinkCircle
 {
-    private ColorPink $color;
-
-    public function __construct(ColorPink $color)
+    public function __construct(private ColorPink $color)
     {
-        $this->color = $color;
     }
 
     public function getColor(): ColorPink
diff --git a/tests/Support/ScalarConstructorArgument.php b/tests/Support/ScalarConstructorArgument.php
index 2eb0321d..02a17532 100644
--- a/tests/Support/ScalarConstructorArgument.php
+++ b/tests/Support/ScalarConstructorArgument.php
@@ -6,11 +6,8 @@
 
 final class ScalarConstructorArgument
 {
-    private string $name;
-
-    public function __construct(string $name)
+    public function __construct(private string $name)
     {
-        $this->name = $name;
     }
 
     public function getName(): string
diff --git a/tests/Support/TwoParametersDependency.php b/tests/Support/TwoParametersDependency.php
index 6b208dca..c0661456 100644
--- a/tests/Support/TwoParametersDependency.php
+++ b/tests/Support/TwoParametersDependency.php
@@ -6,14 +6,8 @@
 
 final class TwoParametersDependency
 {
-    private string $firstParameter;
-
-    private string $secondParameter;
-
-    public function __construct(string $firstParameter, string $secondParameter)
+    public function __construct(private string $firstParameter, private string $secondParameter)
     {
-        $this->firstParameter = $firstParameter;
-        $this->secondParameter = $secondParameter;
     }
 
     public function getFirstParameter(): string
diff --git a/tests/Support/VariadicConstructor.php b/tests/Support/VariadicConstructor.php
index 13006a8f..bbd29b48 100644
--- a/tests/Support/VariadicConstructor.php
+++ b/tests/Support/VariadicConstructor.php
@@ -6,22 +6,10 @@
 
 final class VariadicConstructor
 {
-    /**
-     * @var mixed
-     */
-    private $first;
-
-    private EngineInterface $engine;
     private array $parameters;
 
-    /**
-     * @param mixed $first
-     * @param mixed ...$parameters
-     */
-    public function __construct($first, EngineInterface $engine, ...$parameters)
+    public function __construct(private mixed $first, private EngineInterface $engine, mixed ...$parameters)
     {
-        $this->first = $first;
-        $this->engine = $engine;
         $this->parameters = $parameters;
     }