diff --git a/AcceptHeader.php b/AcceptHeader.php
index bbbd62a6d..c3c8d0c35 100644
--- a/AcceptHeader.php
+++ b/AcceptHeader.php
@@ -11,6 +11,9 @@
 
 namespace Symfony\Component\HttpFoundation;
 
+// Help opcache.preload discover always-needed symbols
+class_exists(AcceptHeaderItem::class);
+
 /**
  * Represents an Accept-* header.
  *
diff --git a/File/File.php b/File/File.php
index 4906588a7..c72a6d991 100644
--- a/File/File.php
+++ b/File/File.php
@@ -91,7 +91,7 @@ public function move($directory, $name = null)
         $renamed = rename($this->getPathname(), $target);
         restore_error_handler();
         if (!$renamed) {
-            throw new FileException(sprintf('Could not move the file "%s" to "%s" (%s)', $this->getPathname(), $target, strip_tags($error)));
+            throw new FileException(sprintf('Could not move the file "%s" to "%s" (%s).', $this->getPathname(), $target, strip_tags($error)));
         }
 
         @chmod($target, 0666 & ~umask());
@@ -106,10 +106,10 @@ protected function getTargetFile($directory, $name = null)
     {
         if (!is_dir($directory)) {
             if (false === @mkdir($directory, 0777, true) && !is_dir($directory)) {
-                throw new FileException(sprintf('Unable to create the "%s" directory', $directory));
+                throw new FileException(sprintf('Unable to create the "%s" directory.', $directory));
             }
         } elseif (!is_writable($directory)) {
-            throw new FileException(sprintf('Unable to write in the "%s" directory', $directory));
+            throw new FileException(sprintf('Unable to write in the "%s" directory.', $directory));
         }
 
         $target = rtrim($directory, '/\\').\DIRECTORY_SEPARATOR.(null === $name ? $this->getBasename() : $this->getName($name));
diff --git a/File/MimeType/MimeTypeGuesser.php b/File/MimeType/MimeTypeGuesser.php
index ece2109ca..65b4b25be 100644
--- a/File/MimeType/MimeTypeGuesser.php
+++ b/File/MimeType/MimeTypeGuesser.php
@@ -130,7 +130,7 @@ public function guess($path)
         }
 
         if (2 === \count($this->guessers) && !FileBinaryMimeTypeGuesser::isSupported() && !FileinfoMimeTypeGuesser::isSupported()) {
-            throw new \LogicException('Unable to guess the mime type as no guessers are available (Did you enable the php_fileinfo extension?)');
+            throw new \LogicException('Unable to guess the mime type as no guessers are available (Did you enable the php_fileinfo extension?).');
         }
 
         return null;
diff --git a/File/UploadedFile.php b/File/UploadedFile.php
index 0c67f8907..36fd1e65c 100644
--- a/File/UploadedFile.php
+++ b/File/UploadedFile.php
@@ -208,7 +208,7 @@ public function move($directory, $name = null)
             $moved = move_uploaded_file($this->getPathname(), $target);
             restore_error_handler();
             if (!$moved) {
-                throw new FileException(sprintf('Could not move the file "%s" to "%s" (%s)', $this->getPathname(), $target, strip_tags($error)));
+                throw new FileException(sprintf('Could not move the file "%s" to "%s" (%s).', $this->getPathname(), $target, strip_tags($error)));
             }
 
             @chmod($target, 0666 & ~umask());
diff --git a/HeaderBag.php b/HeaderBag.php
index 9ffe6f4fe..da794554b 100644
--- a/HeaderBag.php
+++ b/HeaderBag.php
@@ -219,7 +219,7 @@ public function getDate($key, \DateTime $default = null)
         }
 
         if (false === $date = \DateTime::createFromFormat(DATE_RFC2822, $value)) {
-            throw new \RuntimeException(sprintf('The %s HTTP header is not parseable (%s).', $key, $value));
+            throw new \RuntimeException(sprintf('The "%s" HTTP header is not parseable (%s).', $key, $value));
         }
 
         return $date;
diff --git a/Request.php b/Request.php
index 6690b9b22..a5e50eb79 100644
--- a/Request.php
+++ b/Request.php
@@ -15,6 +15,14 @@
 use Symfony\Component\HttpFoundation\Exception\SuspiciousOperationException;
 use Symfony\Component\HttpFoundation\Session\SessionInterface;
 
+// Help opcache.preload discover always-needed symbols
+class_exists(AcceptHeader::class);
+class_exists(FileBag::class);
+class_exists(HeaderBag::class);
+class_exists(HeaderUtils::class);
+class_exists(ParameterBag::class);
+class_exists(ServerBag::class);
+
 /**
  * Request represents an HTTP request.
  *
@@ -725,7 +733,7 @@ public function getSession()
 
         if (null === $session) {
             @trigger_error(sprintf('Calling "%s()" when no session has been set is deprecated since Symfony 4.1 and will throw an exception in 5.0. Use "hasSession()" instead.', __METHOD__), E_USER_DEPRECATED);
-            // throw new \BadMethodCallException('Session has not been set');
+            // throw new \BadMethodCallException('Session has not been set.');
         }
 
         return $session;
diff --git a/Response.php b/Response.php
index b267cd8ce..714109d53 100644
--- a/Response.php
+++ b/Response.php
@@ -11,6 +11,9 @@
 
 namespace Symfony\Component\HttpFoundation;
 
+// Help opcache.preload discover always-needed symbols
+class_exists(ResponseHeaderBag::class);
+
 /**
  * Response represents an HTTP response.
  *
diff --git a/ResponseHeaderBag.php b/ResponseHeaderBag.php
index cdc669904..e71034aba 100644
--- a/ResponseHeaderBag.php
+++ b/ResponseHeaderBag.php
@@ -252,10 +252,13 @@ public function getCookies($format = self::COOKIES_FLAT)
      * @param string $domain
      * @param bool   $secure
      * @param bool   $httpOnly
+     * @param string $sameSite
      */
-    public function clearCookie($name, $path = '/', $domain = null, $secure = false, $httpOnly = true)
+    public function clearCookie($name, $path = '/', $domain = null, $secure = false, $httpOnly = true/*, $sameSite = null*/)
     {
-        $this->setCookie(new Cookie($name, null, 1, $path, $domain, $secure, $httpOnly, false, null));
+        $sameSite = \func_num_args() > 5 ? func_get_arg(5) : null;
+
+        $this->setCookie(new Cookie($name, null, 1, $path, $domain, $secure, $httpOnly, false, $sameSite));
     }
 
     /**
diff --git a/Session/Session.php b/Session/Session.php
index 2192c629e..b6973aaab 100644
--- a/Session/Session.php
+++ b/Session/Session.php
@@ -18,6 +18,11 @@
 use Symfony\Component\HttpFoundation\Session\Storage\NativeSessionStorage;
 use Symfony\Component\HttpFoundation\Session\Storage\SessionStorageInterface;
 
+// Help opcache.preload discover always-needed symbols
+class_exists(AttributeBag::class);
+class_exists(FlashBag::class);
+class_exists(SessionBagProxy::class);
+
 /**
  * @author Fabien Potencier <fabien@symfony.com>
  * @author Drak <drak@zikula.org>
diff --git a/Session/Storage/Handler/MemcachedSessionHandler.php b/Session/Storage/Handler/MemcachedSessionHandler.php
index a399be5fd..6711e0a55 100644
--- a/Session/Storage/Handler/MemcachedSessionHandler.php
+++ b/Session/Storage/Handler/MemcachedSessionHandler.php
@@ -47,7 +47,7 @@ public function __construct(\Memcached $memcached, array $options = [])
         $this->memcached = $memcached;
 
         if ($diff = array_diff(array_keys($options), ['prefix', 'expiretime'])) {
-            throw new \InvalidArgumentException(sprintf('The following options are not supported "%s"', implode(', ', $diff)));
+            throw new \InvalidArgumentException(sprintf('The following options are not supported "%s".', implode(', ', $diff)));
         }
 
         $this->ttl = isset($options['expiretime']) ? (int) $options['expiretime'] : 86400;
diff --git a/Session/Storage/Handler/MongoDbSessionHandler.php b/Session/Storage/Handler/MongoDbSessionHandler.php
index 27e080021..6cb884778 100644
--- a/Session/Storage/Handler/MongoDbSessionHandler.php
+++ b/Session/Storage/Handler/MongoDbSessionHandler.php
@@ -66,7 +66,7 @@ class MongoDbSessionHandler extends AbstractSessionHandler
     public function __construct(\MongoDB\Client $mongo, array $options)
     {
         if (!isset($options['database']) || !isset($options['collection'])) {
-            throw new \InvalidArgumentException('You must provide the "database" and "collection" option for MongoDBSessionHandler');
+            throw new \InvalidArgumentException('You must provide the "database" and "collection" option for MongoDBSessionHandler.');
         }
 
         $this->mongo = $mongo;
diff --git a/Session/Storage/Handler/NativeFileSessionHandler.php b/Session/Storage/Handler/NativeFileSessionHandler.php
index bdfc9d819..effc9db54 100644
--- a/Session/Storage/Handler/NativeFileSessionHandler.php
+++ b/Session/Storage/Handler/NativeFileSessionHandler.php
@@ -38,7 +38,7 @@ public function __construct(string $savePath = null)
 
         if ($count = substr_count($savePath, ';')) {
             if ($count > 2) {
-                throw new \InvalidArgumentException(sprintf('Invalid argument $savePath \'%s\'', $savePath));
+                throw new \InvalidArgumentException(sprintf('Invalid argument $savePath \'%s\'.', $savePath));
             }
 
             // characters after last ';' are the path
@@ -46,7 +46,7 @@ public function __construct(string $savePath = null)
         }
 
         if ($baseDir && !is_dir($baseDir) && !@mkdir($baseDir, 0777, true) && !is_dir($baseDir)) {
-            throw new \RuntimeException(sprintf('Session Storage was not able to create directory "%s"', $baseDir));
+            throw new \RuntimeException(sprintf('Session Storage was not able to create directory "%s".', $baseDir));
         }
 
         ini_set('session.save_path', $savePath);
diff --git a/Session/Storage/Handler/PdoSessionHandler.php b/Session/Storage/Handler/PdoSessionHandler.php
index 034c02e5c..330ac7f2a 100644
--- a/Session/Storage/Handler/PdoSessionHandler.php
+++ b/Session/Storage/Handler/PdoSessionHandler.php
@@ -174,7 +174,7 @@ public function __construct($pdoOrDsn = null, array $options = [])
     {
         if ($pdoOrDsn instanceof \PDO) {
             if (\PDO::ERRMODE_EXCEPTION !== $pdoOrDsn->getAttribute(\PDO::ATTR_ERRMODE)) {
-                throw new \InvalidArgumentException(sprintf('"%s" requires PDO error mode attribute be set to throw Exceptions (i.e. $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION))', __CLASS__));
+                throw new \InvalidArgumentException(sprintf('"%s" requires PDO error mode attribute be set to throw Exceptions (i.e. $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION)).', __CLASS__));
             }
 
             $this->pdo = $pdoOrDsn;
@@ -468,7 +468,7 @@ private function buildDsnFromUrl(string $dsnOrUrl): string
         }
 
         if (!isset($params['scheme'])) {
-            throw new \InvalidArgumentException('URLs without scheme are not supported to configure the PdoSessionHandler');
+            throw new \InvalidArgumentException('URLs without scheme are not supported to configure the PdoSessionHandler.');
         }
 
         $driverAliasMap = [
diff --git a/Session/Storage/Handler/RedisSessionHandler.php b/Session/Storage/Handler/RedisSessionHandler.php
index e5be90d5f..699d6da6f 100644
--- a/Session/Storage/Handler/RedisSessionHandler.php
+++ b/Session/Storage/Handler/RedisSessionHandler.php
@@ -54,11 +54,11 @@ public function __construct($redis, array $options = [])
             !$redis instanceof RedisProxy &&
             !$redis instanceof RedisClusterProxy
         ) {
-            throw new \InvalidArgumentException(sprintf('%s() expects parameter 1 to be Redis, RedisArray, RedisCluster or Predis\ClientInterface, %s given', __METHOD__, \is_object($redis) ? \get_class($redis) : \gettype($redis)));
+            throw new \InvalidArgumentException(sprintf('"%s()" expects parameter 1 to be Redis, RedisArray, RedisCluster or Predis\ClientInterface, "%s" given.', __METHOD__, \is_object($redis) ? \get_class($redis) : \gettype($redis)));
         }
 
         if ($diff = array_diff(array_keys($options), ['prefix', 'ttl'])) {
-            throw new \InvalidArgumentException(sprintf('The following options are not supported "%s"', implode(', ', $diff)));
+            throw new \InvalidArgumentException(sprintf('The following options are not supported "%s".', implode(', ', $diff)));
         }
 
         $this->redis = $redis;
diff --git a/Session/Storage/Handler/SessionHandlerFactory.php b/Session/Storage/Handler/SessionHandlerFactory.php
index b92bd0ffd..a5ebd29eb 100644
--- a/Session/Storage/Handler/SessionHandlerFactory.php
+++ b/Session/Storage/Handler/SessionHandlerFactory.php
@@ -27,7 +27,7 @@ class SessionHandlerFactory
     public static function createHandler($connection): AbstractSessionHandler
     {
         if (!\is_string($connection) && !\is_object($connection)) {
-            throw new \TypeError(sprintf('Argument 1 passed to %s() must be a string or a connection object, %s given.', __METHOD__, \gettype($connection)));
+            throw new \TypeError(sprintf('Argument 1 passed to "%s()" must be a string or a connection object, "%s" given.', __METHOD__, \gettype($connection)));
         }
 
         switch (true) {
@@ -46,7 +46,7 @@ public static function createHandler($connection): AbstractSessionHandler
                 return new PdoSessionHandler($connection);
 
             case !\is_string($connection):
-                throw new \InvalidArgumentException(sprintf('Unsupported Connection: %s.', \get_class($connection)));
+                throw new \InvalidArgumentException(sprintf('Unsupported Connection: "%s".', \get_class($connection)));
             case 0 === strpos($connection, 'file://'):
                 return new StrictSessionHandler(new NativeFileSessionHandler(substr($connection, 7)));
 
@@ -80,6 +80,6 @@ public static function createHandler($connection): AbstractSessionHandler
                 return new PdoSessionHandler($connection);
         }
 
-        throw new \InvalidArgumentException(sprintf('Unsupported Connection: %s.', $connection));
+        throw new \InvalidArgumentException(sprintf('Unsupported Connection: "%s".', $connection));
     }
 }
diff --git a/Session/Storage/MockArraySessionStorage.php b/Session/Storage/MockArraySessionStorage.php
index 37b6f145b..db8f85e75 100644
--- a/Session/Storage/MockArraySessionStorage.php
+++ b/Session/Storage/MockArraySessionStorage.php
@@ -148,7 +148,7 @@ public function setName($name)
     public function save()
     {
         if (!$this->started || $this->closed) {
-            throw new \RuntimeException('Trying to save a session that was not started yet or was already closed');
+            throw new \RuntimeException('Trying to save a session that was not started yet or was already closed.');
         }
         // nothing to do since we don't persist the session data
         $this->closed = false;
@@ -186,7 +186,7 @@ public function registerBag(SessionBagInterface $bag)
     public function getBag($name)
     {
         if (!isset($this->bags[$name])) {
-            throw new \InvalidArgumentException(sprintf('The SessionBagInterface %s is not registered.', $name));
+            throw new \InvalidArgumentException(sprintf('The SessionBagInterface "%s" is not registered.', $name));
         }
 
         if (!$this->started) {
diff --git a/Session/Storage/MockFileSessionStorage.php b/Session/Storage/MockFileSessionStorage.php
index 02fe4dad4..c96b3cd9d 100644
--- a/Session/Storage/MockFileSessionStorage.php
+++ b/Session/Storage/MockFileSessionStorage.php
@@ -37,7 +37,7 @@ public function __construct(string $savePath = null, string $name = 'MOCKSESSID'
         }
 
         if (!is_dir($savePath) && !@mkdir($savePath, 0777, true) && !is_dir($savePath)) {
-            throw new \RuntimeException(sprintf('Session Storage was not able to create directory "%s"', $savePath));
+            throw new \RuntimeException(sprintf('Session Storage was not able to create directory "%s".', $savePath));
         }
 
         $this->savePath = $savePath;
@@ -87,7 +87,7 @@ public function regenerate($destroy = false, $lifetime = null)
     public function save()
     {
         if (!$this->started) {
-            throw new \RuntimeException('Trying to save a session that was not started yet or was already closed');
+            throw new \RuntimeException('Trying to save a session that was not started yet or was already closed.');
         }
 
         $data = $this->data;
diff --git a/Session/Storage/NativeSessionStorage.php b/Session/Storage/NativeSessionStorage.php
index 4085bd6ef..54933d953 100644
--- a/Session/Storage/NativeSessionStorage.php
+++ b/Session/Storage/NativeSessionStorage.php
@@ -17,6 +17,11 @@
 use Symfony\Component\HttpFoundation\Session\Storage\Proxy\AbstractProxy;
 use Symfony\Component\HttpFoundation\Session\Storage\Proxy\SessionHandlerProxy;
 
+// Help opcache.preload discover always-needed symbols
+class_exists(MetadataBag::class);
+class_exists(StrictSessionHandler::class);
+class_exists(SessionHandlerProxy::class);
+
 /**
  * This provides a base class for session attribute storage.
  *
@@ -149,7 +154,7 @@ public function start()
 
         // ok to try and start the session
         if (!session_start()) {
-            throw new \RuntimeException('Failed to start the session');
+            throw new \RuntimeException('Failed to start the session.');
         }
 
         if (null !== $this->emulateSameSite) {
@@ -311,7 +316,7 @@ public function registerBag(SessionBagInterface $bag)
     public function getBag($name)
     {
         if (!isset($this->bags[$name])) {
-            throw new \InvalidArgumentException(sprintf('The SessionBagInterface %s is not registered.', $name));
+            throw new \InvalidArgumentException(sprintf('The SessionBagInterface "%s" is not registered.', $name));
         }
 
         if (!$this->started && $this->saveHandler->isActive()) {
diff --git a/Session/Storage/Proxy/AbstractProxy.php b/Session/Storage/Proxy/AbstractProxy.php
index cd0635a16..b9c2682b3 100644
--- a/Session/Storage/Proxy/AbstractProxy.php
+++ b/Session/Storage/Proxy/AbstractProxy.php
@@ -88,7 +88,7 @@ public function getId()
     public function setId($id)
     {
         if ($this->isActive()) {
-            throw new \LogicException('Cannot change the ID of an active session');
+            throw new \LogicException('Cannot change the ID of an active session.');
         }
 
         session_id($id);
@@ -114,7 +114,7 @@ public function getName()
     public function setName($name)
     {
         if ($this->isActive()) {
-            throw new \LogicException('Cannot change the name of an active session');
+            throw new \LogicException('Cannot change the name of an active session.');
         }
 
         session_name($name);
diff --git a/Tests/ResponseHeaderBagTest.php b/Tests/ResponseHeaderBagTest.php
index 4d9244122..18b3c36a6 100644
--- a/Tests/ResponseHeaderBagTest.php
+++ b/Tests/ResponseHeaderBagTest.php
@@ -128,6 +128,14 @@ public function testClearCookieSecureNotHttpOnly()
         $this->assertSetCookieHeader('foo=deleted; expires='.gmdate('D, d-M-Y H:i:s T', time() - 31536001).'; Max-Age=0; path=/; secure', $bag);
     }
 
+    public function testClearCookieSamesite()
+    {
+        $bag = new ResponseHeaderBag([]);
+
+        $bag->clearCookie('foo', '/', null, true, false, 'none');
+        $this->assertSetCookieHeader('foo=deleted; expires='.gmdate('D, d-M-Y H:i:s T', time() - 31536001).'; Max-Age=0; path=/; secure; samesite=none', $bag);
+    }
+
     public function testReplace()
     {
         $bag = new ResponseHeaderBag([]);