diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/Command/RouterMatchCommandTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/Command/RouterMatchCommandTest.php
index e8d31778a31a..a04ef46a90f3 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/Command/RouterMatchCommandTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/Command/RouterMatchCommandTest.php
@@ -96,11 +96,7 @@ private function getKernel()
             ->expects($this->atLeastOnce())
             ->method('has')
             ->will($this->returnCallback(function ($id) {
-                if ('console.command_loader' === $id) {
-                    return false;
-                }
-
-                return true;
+                return 'console.command_loader' !== $id;
             }))
         ;
         $container
diff --git a/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php b/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php
index 24db5d504ab6..bdb62a4bb380 100644
--- a/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php
@@ -13,13 +13,12 @@
 
 use Psr\SimpleCache\CacheInterface;
 use Symfony\Component\Cache\PruneableInterface;
-use Symfony\Component\Cache\ResettableInterface;
 use Symfony\Component\Cache\Traits\ProxyTrait;
 
 /**
  * @author Nicolas Grekas <p@tchwork.com>
  */
-class SimpleCacheAdapter extends AbstractAdapter implements PruneableInterface, ResettableInterface
+class SimpleCacheAdapter extends AbstractAdapter implements PruneableInterface
 {
     use ProxyTrait;
 
diff --git a/src/Symfony/Component/Dotenv/Dotenv.php b/src/Symfony/Component/Dotenv/Dotenv.php
index d21e0435062b..b43529abdfc3 100644
--- a/src/Symfony/Component/Dotenv/Dotenv.php
+++ b/src/Symfony/Component/Dotenv/Dotenv.php
@@ -33,7 +33,6 @@ final class Dotenv
     private $lineno;
     private $data;
     private $end;
-    private $state;
     private $values;
 
     /**
@@ -111,27 +110,27 @@ public function parse($data, $path = '.env')
         $this->lineno = 1;
         $this->cursor = 0;
         $this->end = \strlen($this->data);
-        $this->state = self::STATE_VARNAME;
+        $state = self::STATE_VARNAME;
         $this->values = [];
         $name = '';
 
         $this->skipEmptyLines();
 
         while ($this->cursor < $this->end) {
-            switch ($this->state) {
+            switch ($state) {
                 case self::STATE_VARNAME:
                     $name = $this->lexVarname();
-                    $this->state = self::STATE_VALUE;
+                    $state = self::STATE_VALUE;
                     break;
 
                 case self::STATE_VALUE:
                     $this->values[$name] = $this->lexValue();
-                    $this->state = self::STATE_VARNAME;
+                    $state = self::STATE_VARNAME;
                     break;
             }
         }
 
-        if (self::STATE_VALUE === $this->state) {
+        if (self::STATE_VALUE === $state) {
             $this->values[$name] = '';
         }
 
diff --git a/src/Symfony/Component/HttpKernel/EventListener/DebugHandlersListener.php b/src/Symfony/Component/HttpKernel/EventListener/DebugHandlersListener.php
index 77f9e2f61839..fed9e7e3febe 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/DebugHandlersListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/DebugHandlersListener.php
@@ -105,7 +105,7 @@ public function configure(Event $event = null)
                 if (method_exists($kernel = $event->getKernel(), 'terminateWithException')) {
                     $request = $event->getRequest();
                     $hasRun = &$this->hasTerminatedWithException;
-                    $this->exceptionHandler = function (\Exception $e) use ($kernel, $request, &$hasRun) {
+                    $this->exceptionHandler = static function (\Exception $e) use ($kernel, $request, &$hasRun) {
                         if ($hasRun) {
                             throw $e;
                         }
diff --git a/src/Symfony/Component/HttpKernel/HttpCache/ResponseCacheStrategy.php b/src/Symfony/Component/HttpKernel/HttpCache/ResponseCacheStrategy.php
index 862bac557dd7..1efad607e827 100644
--- a/src/Symfony/Component/HttpKernel/HttpCache/ResponseCacheStrategy.php
+++ b/src/Symfony/Component/HttpKernel/HttpCache/ResponseCacheStrategy.php
@@ -215,7 +215,7 @@ private function storeRelativeAgeDirective($directive, $value, $age)
         }
 
         if (false !== $this->ageDirectives[$directive]) {
-            $value = $value - $age;
+            $value -= $age;
             $this->ageDirectives[$directive] = null !== $this->ageDirectives[$directive] ? min($this->ageDirectives[$directive], $value) : $value;
         }
     }
diff --git a/src/Symfony/Component/Security/Guard/Token/PostAuthenticationGuardToken.php b/src/Symfony/Component/Security/Guard/Token/PostAuthenticationGuardToken.php
index 17e01ebf8dd0..00048226b6aa 100644
--- a/src/Symfony/Component/Security/Guard/Token/PostAuthenticationGuardToken.php
+++ b/src/Symfony/Component/Security/Guard/Token/PostAuthenticationGuardToken.php
@@ -47,7 +47,7 @@ public function __construct(UserInterface $user, $providerKey, array $roles)
 
         // this token is meant to be used after authentication success, so it is always authenticated
         // you could set it as non authenticated later if you need to
-        parent::setAuthenticated(true);
+        $this->setAuthenticated(true);
     }
 
     /**
diff --git a/src/Symfony/Component/Workflow/Exception/InvalidTokenConfigurationException.php b/src/Symfony/Component/Workflow/Exception/InvalidTokenConfigurationException.php
index 681d7a8bba52..a70fd4c98ddf 100644
--- a/src/Symfony/Component/Workflow/Exception/InvalidTokenConfigurationException.php
+++ b/src/Symfony/Component/Workflow/Exception/InvalidTokenConfigurationException.php
@@ -16,6 +16,6 @@
  *
  * @author Matt Johnson <matj1985@gmail.com>
  */
-class InvalidTokenConfigurationException extends LogicException implements ExceptionInterface
+class InvalidTokenConfigurationException extends LogicException
 {
 }