diff --git a/src/Command/ScheduleTaskCommand.php b/src/Command/ScheduleTaskCommand.php
index 40b4b54..522dbc2 100644
--- a/src/Command/ScheduleTaskCommand.php
+++ b/src/Command/ScheduleTaskCommand.php
@@ -80,16 +80,16 @@ protected function execute(InputInterface $input, OutputInterface $output)
 
         $taskBuilder = $this->scheduler->createTask($handlerClass, $workload);
 
-        if ($cronExpression !== null) {
+        if (null !== $cronExpression) {
             $endDate = null;
-            if ($endDateString !== null) {
+            if (null !== $endDateString) {
                 $endDate = new \DateTime($endDateString);
             }
 
             $taskBuilder->cron($cronExpression, new \DateTime(), $endDate);
         }
 
-        if ($executionDateString !== null) {
+        if (null !== $executionDateString) {
             $taskBuilder->executeAt(new \DateTime($executionDateString));
         }
 
diff --git a/src/DependencyInjection/HandlerCompilerPass.php b/src/DependencyInjection/HandlerCompilerPass.php
index 1a953e1..f8f9284 100644
--- a/src/DependencyInjection/HandlerCompilerPass.php
+++ b/src/DependencyInjection/HandlerCompilerPass.php
@@ -21,6 +21,7 @@
 class HandlerCompilerPass implements CompilerPassInterface
 {
     const REGISTRY_ID = 'task.handler.factory';
+
     const HANDLER_TAG = 'task.handler';
 
     /**
diff --git a/src/Executor/SeparateProcessException.php b/src/Executor/SeparateProcessException.php
index ac7eda6..d4e1865 100644
--- a/src/Executor/SeparateProcessException.php
+++ b/src/Executor/SeparateProcessException.php
@@ -26,6 +26,8 @@ class SeparateProcessException extends \Exception
      */
     public function __construct($errorOutput)
     {
+        parent::__construct($errorOutput);
+
         $this->errorOutput = $errorOutput;
     }
 
diff --git a/src/Executor/SeparateProcessExecutor.php b/src/Executor/SeparateProcessExecutor.php
index cd56c86..9a4d76f 100644
--- a/src/Executor/SeparateProcessExecutor.php
+++ b/src/Executor/SeparateProcessExecutor.php
@@ -131,7 +131,7 @@ private function handle(TaskExecutionInterface $execution)
      */
     private function createException($errorOutput)
     {
-        if (strpos($errorOutput, FailedException::class) !== 0) {
+        if (0 !== strpos($errorOutput, FailedException::class)) {
             return new SeparateProcessException($errorOutput);
         }
 
diff --git a/tests/Functional/Command/ScheduleSystemTasksCommandTest.php b/tests/Functional/Command/ScheduleSystemTasksCommandTest.php
index 3c935a0..2ff7fff 100644
--- a/tests/Functional/Command/ScheduleSystemTasksCommandTest.php
+++ b/tests/Functional/Command/ScheduleSystemTasksCommandTest.php
@@ -10,7 +10,7 @@ class ScheduleSystemTasksCommandTest extends BaseCommandTestCase
     public function setUp()
     {
         self::bootKernel();
-        if (self::$kernel->getContainer()->getParameter('kernel.storage') !== 'doctrine') {
+        if ('doctrine' !== self::$kernel->getContainer()->getParameter('kernel.storage')) {
             return $this->markTestSkipped('This testcase will only be called for doctrine storage.');
         }
 
diff --git a/tests/Functional/Entity/TaskRepositoryTest.php b/tests/Functional/Entity/TaskRepositoryTest.php
index 760e02f..b02ed0f 100644
--- a/tests/Functional/Entity/TaskRepositoryTest.php
+++ b/tests/Functional/Entity/TaskRepositoryTest.php
@@ -21,7 +21,7 @@ public function setUp()
 
     public function testFindBySystemKey()
     {
-        if (self::$kernel->getContainer()->getParameter('kernel.storage') !== 'doctrine') {
+        if ('doctrine' !== self::$kernel->getContainer()->getParameter('kernel.storage')) {
             return $this->markTestSkipped('This testcase will only be called for doctrine storage.');
         }
 
@@ -36,7 +36,7 @@ public function testFindBySystemKey()
 
     public function testFindBySystemKeyNotFound()
     {
-        if (self::$kernel->getContainer()->getParameter('kernel.storage') !== 'doctrine') {
+        if ('doctrine' !== self::$kernel->getContainer()->getParameter('kernel.storage')) {
             return $this->markTestSkipped('This testcase will only be called for doctrine storage.');
         }
 
@@ -48,7 +48,7 @@ public function testFindBySystemKeyNotFound()
 
     public function testFindSystemTasks()
     {
-        if (self::$kernel->getContainer()->getParameter('kernel.storage') !== 'doctrine') {
+        if ('doctrine' !== self::$kernel->getContainer()->getParameter('kernel.storage')) {
             return $this->markTestSkipped('This testcase will only be called for doctrine storage.');
         }
 
diff --git a/tests/app/TestKernel.php b/tests/app/TestKernel.php
index 2d49551..d77316d 100644
--- a/tests/app/TestKernel.php
+++ b/tests/app/TestKernel.php
@@ -44,7 +44,7 @@ public function registerBundles()
     public function registerContainerConfiguration(LoaderInterface $loader)
     {
         $this->storage = getenv(self::STORAGE_VAR_NAME);
-        if ($this->storage === false) {
+        if (false === $this->storage) {
             $this->storage = 'array';
         }