diff --git a/Tests/Response/AbstractResponse.php b/Tests/Response/AbstractResponse.php
index f8c4b7d..63cce35 100644
--- a/Tests/Response/AbstractResponse.php
+++ b/Tests/Response/AbstractResponse.php
@@ -86,7 +86,7 @@ abstract class AbstractResponse extends ApiTestCase
      */
     protected function checkProperties($expected, $propertyName, $methodName)
     {
-        /** @var Response $response */
+        /** @var Response|MockObject $responseMock */
         $responseMock = $this->getMockBuilder($this->testClassName)
             ->disableOriginalConstructor()
             ->onlyMethods(['getContent'])
diff --git a/Tests/ValueObject/SenderTest.php b/Tests/ValueObject/SenderTest.php
index f4f6bdb..b523fc8 100644
--- a/Tests/ValueObject/SenderTest.php
+++ b/Tests/ValueObject/SenderTest.php
@@ -29,7 +29,7 @@ use ReflectionException;
 
 class SenderTest extends ApiTestCase
 {
-    /** @var Sender */
+    /** @var Sender|MockObject */
     public $sender;
 
     private $phoneNumberFixture;
@@ -48,7 +48,6 @@ class SenderTest extends ApiTestCase
         $example = $phoneUtil->getExampleNumberForType($this->phoneCountryFixture, PhoneNumberType::MOBILE);
         $this->phoneNumberFixture = $phoneUtil->format($example, PhoneNumberFormat::NATIONAL);
 
-        /** @var Sender|MockObject sender */
         $this->sender = new Sender($this->phoneNumberFixture, $this->phoneCountryFixture);
     }
 
diff --git a/Tests/ValueObject/ValueObjectTest.php b/Tests/ValueObject/ValueObjectTest.php
index f7e513b..13e5707 100644
--- a/Tests/ValueObject/ValueObjectTest.php
+++ b/Tests/ValueObject/ValueObjectTest.php
@@ -26,11 +26,13 @@ use ReflectionException;
 
 class ValueObjectTest extends ApiTestCase
 {
+    /** @var ValueObject|MockObject */
+    public $value;
+
     public function setUp(): void
     {
         parent::setUp();
 
-        /** @var ValueObject|MockObject value */
         $this->value = $this->getMockBuilder(ValueObject::class)
             ->disableOriginalConstructor()
             ->getMock();
diff --git a/phpstan.neon b/phpstan.neon
index a636906..6f108c7 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -2,5 +2,5 @@ parameters:
     paths:
         - src
         - Tests
-    level: 0
-    phpVersion: 70300
\ No newline at end of file
+    level: 2
+    phpVersion: 70300
diff --git a/src/LoggerHandler.php b/src/LoggerHandler.php
index 26b74d7..74c00f7 100644
--- a/src/LoggerHandler.php
+++ b/src/LoggerHandler.php
@@ -38,7 +38,7 @@ class LoggerHandler
     }
 
     /**
-     * @param mixed $logger
+     * @param LoggerInterface $logger
      */
     public function setLogger(LoggerInterface $logger)
     {
diff --git a/src/Request/Request.php b/src/Request/Request.php
index 94dcdd9..1662c5f 100644
--- a/src/Request/Request.php
+++ b/src/Request/Request.php
@@ -422,7 +422,7 @@ abstract class Request implements RequestInterface
     }
 
     /**
-     * @return bool|null
+     * @return bool
      */
     public function doSendAsFlashSms(): bool
     {