diff --git a/Bridge/Laminas/Storage/TableGatewayStorage.php b/Bridge/Laminas/Storage/TableGatewayStorage.php
index 215e420..5d070a7 100644
--- a/Bridge/Laminas/Storage/TableGatewayStorage.php
+++ b/Bridge/Laminas/Storage/TableGatewayStorage.php
@@ -67,10 +67,10 @@ public function __construct($tableGateway, $modelClass, $idField = 'id')
         if ($tableGateway instanceof LaminasTableGateway) {
             $this->tableGateway = $tableGateway;
         } else if ($tableGateway instanceof ZendTableGateway) {
-            @trigger_error(sprintf('Passing an instance of %s as the first argument to %s is deprecated and won\'t be supported in 2.0. Please using Laminas instead.', ZendTableGateway::class, __CLASS__));
+            @trigger_error(sprintf('Passing an instance of %s as the first argument to %s is deprecated and won\'t be supported in 2.0. Please using Laminas instead.', ZendTableGateway::class, self::class));
             $this->tableGateway = $tableGateway;
         } else {
-            throw new \InvalidArgumentException(sprintf('Argument $tableGateway of %s must be an instance of %s or %s, %s given.', __CLASS__, LaminasTableGateway::class, ZendTableGateway::class, (is_object($tableGateway) ? get_class($tableGateway) : gettype($tableGateway))));
+            throw new \InvalidArgumentException(sprintf('Argument $tableGateway of %s must be an instance of %s or %s, %s given.', self::class, LaminasTableGateway::class, ZendTableGateway::class, (is_object($tableGateway) ? get_class($tableGateway) : gettype($tableGateway))));
         }
 
         $this->idField = $idField;
diff --git a/Bridge/PlainPhp/Action/GetHttpRequestAction.php b/Bridge/PlainPhp/Action/GetHttpRequestAction.php
index 4930049..b31a251 100644
--- a/Bridge/PlainPhp/Action/GetHttpRequestAction.php
+++ b/Bridge/PlainPhp/Action/GetHttpRequestAction.php
@@ -16,12 +16,12 @@ public function execute($request)
     {
         RequestNotSupportedException::assertSupports($this, $request);
 
-        $request->method = isset($_SERVER['REQUEST_METHOD']) ? $_SERVER['REQUEST_METHOD'] : 'GET';
+        $request->method = $_SERVER['REQUEST_METHOD'] ?? 'GET';
         $request->query = $_GET;
         $request->request = $_REQUEST;
-        $request->clientIp = isset($_SERVER['REMOTE_ADDR']) ? $_SERVER['REMOTE_ADDR'] : '';
-        $request->uri = isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : '';
-        $request->userAgent = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : '';
+        $request->clientIp = $_SERVER['REMOTE_ADDR'] ?? '';
+        $request->uri = $_SERVER['REQUEST_URI'] ?? '';
+        $request->userAgent = $_SERVER['HTTP_USER_AGENT'] ?? '';
         $request->content = file_get_contents('php://input');
     }
 
diff --git a/Bridge/Spl/ArrayObject.php b/Bridge/Spl/ArrayObject.php
index 9df1093..43dd2cd 100644
--- a/Bridge/Spl/ArrayObject.php
+++ b/Bridge/Spl/ArrayObject.php
@@ -35,7 +35,7 @@ public function __construct($input = array(), $flags = 0, $iterator_class = "Arr
      */
     public function get($key, $default = null)
     {
-        return isset($this[$key]) ? $this[$key] : $default;
+        return $this[$key] ?? $default;
     }
 
     /**
@@ -58,7 +58,7 @@ public function getArray($key, $default = [])
      */
     public function replace($input)
     {
-        if (false == (is_array($input) || $input instanceof \Traversable)) {
+        if (false == (is_iterable($input))) {
             throw new InvalidArgumentException('Invalid input given. Should be an array or instance of \Traversable');
         }
 
@@ -76,7 +76,7 @@ public function replace($input)
      */
     public function defaults($input)
     {
-        if (false == (is_array($input) || $input instanceof \Traversable)) {
+        if (false == (is_iterable($input))) {
             throw new InvalidArgumentException('Invalid input given. Should be an array or instance of \Traversable');
         }
 
diff --git a/Bridge/Symfony/Validator/Constraints/CreditCardDate.php b/Bridge/Symfony/Validator/Constraints/CreditCardDate.php
index 7d402a8..42952de 100644
--- a/Bridge/Symfony/Validator/Constraints/CreditCardDate.php
+++ b/Bridge/Symfony/Validator/Constraints/CreditCardDate.php
@@ -21,7 +21,7 @@ public function __construct($options = null)
         parent::__construct($options);
 
         if (null === $this->min) {
-            throw new MissingOptionsException('Either option "min" must be given for constraint ' . __CLASS__, array('min'));
+            throw new MissingOptionsException('Either option "min" must be given for constraint ' . self::class, array('min'));
         }
 
         if (null !== $this->min) {
diff --git a/Model/Identity.php b/Model/Identity.php
index d800b01..fa00657 100644
--- a/Model/Identity.php
+++ b/Model/Identity.php
@@ -54,7 +54,7 @@ public function serialize()
      */
     public function unserialize($serialized)
     {
-        list($this->id, $this->class) = unserialize($serialized);
+        [$this->id, $this->class] = unserialize($serialized);
     }
 
     public function __serialize(): array
@@ -64,7 +64,7 @@ public function __serialize(): array
 
     public function __unserialize(array $data)
     {
-        list($this->id, $this->class) = $data;
+        [$this->id, $this->class] = $data;
     }
 
     /**
diff --git a/PayumBuilder.php b/PayumBuilder.php
index 5d3c5fa..81764b4 100644
--- a/PayumBuilder.php
+++ b/PayumBuilder.php
@@ -161,7 +161,7 @@ public function addGateway($name, $gateway)
         if ($gateway instanceof GatewayInterface) {
             $this->gateways[$name] = $gateway;
         } elseif (is_array($gateway)) {
-            $currentConfig = isset($this->gatewayConfigs[$name]) ? $this->gatewayConfigs[$name] : [];
+            $currentConfig = $this->gatewayConfigs[$name] ?? [];
             $currentConfig = array_replace_recursive($currentConfig, $gateway);
             if (empty($currentConfig['factory'])) {
                 throw new InvalidArgumentException('Gateway config must have factory set in it and it must not be empty.');
@@ -202,7 +202,7 @@ public function addGatewayFactory($name, $gatewayFactory)
      */
     public function addGatewayFactoryConfig($name, array $config)
     {
-        $currentConfig = isset($this->gatewayFactoryConfigs[$name]) ? $this->gatewayFactoryConfigs[$name] : [];
+        $currentConfig = $this->gatewayFactoryConfigs[$name] ?? [];
         $this->gatewayFactoryConfigs[$name] = array_replace_recursive($currentConfig, $config);
 
         return $this;
@@ -569,7 +569,7 @@ protected function buildGatewayFactories(GatewayFactoryInterface $coreGatewayFac
         foreach ($map as $name => $factoryClass) {
             if (class_exists($factoryClass)) {
                 $gatewayFactories[$name] = new $factoryClass(
-                    isset($this->gatewayFactoryConfigs[$name]) ? $this->gatewayFactoryConfigs[$name] : [],
+                    $this->gatewayFactoryConfigs[$name] ?? [],
                     $coreGatewayFactory
                 );
             }
@@ -588,7 +588,7 @@ protected function buildAddedGatewayFactories(GatewayFactoryInterface $coreGatew
         $gatewayFactories = [];
         foreach ($this->gatewayFactories as $name => $factory) {
             if (is_callable($factory)) {
-                $config = isset($this->gatewayFactoryConfigs[$name]) ? $this->gatewayFactoryConfigs[$name] : [];
+                $config = $this->gatewayFactoryConfigs[$name] ?? [];
 
                 $factory = call_user_func($factory, $config, $coreGatewayFactory);
             }
diff --git a/Tests/Debug/HumanifyTest.php b/Tests/Debug/HumanifyTest.php
index 0c137f4..8d3c246 100644
--- a/Tests/Debug/HumanifyTest.php
+++ b/Tests/Debug/HumanifyTest.php
@@ -49,7 +49,7 @@ public function shouldReturnObjectShortClassOnValueIfObjectPassedAndShortClassFl
      */
     public function shouldReturnObjectClassOnValueIfObjectPassedAndShortClassFlagSetFalse()
     {
-        $this->assertEquals(__CLASS__, Humanify::value($this, false));
+        $this->assertEquals(self::class, Humanify::value($this, false));
     }
 
     /**