diff --git a/src/Symfony/Component/Cache/CacheItem.php b/src/Symfony/Component/Cache/CacheItem.php
index 8145c49de257c..9623458293e95 100644
--- a/src/Symfony/Component/Cache/CacheItem.php
+++ b/src/Symfony/Component/Cache/CacheItem.php
@@ -151,11 +151,9 @@ public function getMetadata(): array
     /**
      * Validates a cache key according to PSR-6.
      *
-     * @param string $key The key to validate
-     *
      * @throws InvalidArgumentException When $key is not valid
      */
-    public static function validateKey($key): string
+    public static function validateKey(mixed $key): string
     {
         if (!\is_string($key)) {
             throw new InvalidArgumentException(sprintf('Cache key must be string, "%s" given.', get_debug_type($key)));
diff --git a/src/Symfony/Component/Cache/Messenger/EarlyExpirationMessage.php b/src/Symfony/Component/Cache/Messenger/EarlyExpirationMessage.php
index e25c07e9a66be..94e3b97e88409 100644
--- a/src/Symfony/Component/Cache/Messenger/EarlyExpirationMessage.php
+++ b/src/Symfony/Component/Cache/Messenger/EarlyExpirationMessage.php
@@ -88,7 +88,7 @@ public function findCallback(ReverseContainer $reverseContainer): callable
         return $callback;
     }
 
-    private function __construct(CacheItem $item, string $pool, $callback)
+    private function __construct(CacheItem $item, string $pool, string|array $callback)
     {
         $this->item = $item;
         $this->pool = $pool;
diff --git a/src/Symfony/Component/Cache/Traits/AbstractAdapterTrait.php b/src/Symfony/Component/Cache/Traits/AbstractAdapterTrait.php
index 30f76c089db17..d9374e8ee8ed3 100644
--- a/src/Symfony/Component/Cache/Traits/AbstractAdapterTrait.php
+++ b/src/Symfony/Component/Cache/Traits/AbstractAdapterTrait.php
@@ -291,14 +291,12 @@ public function saveDeferred(CacheItemInterface $item)
      *
      * Calling this method also clears the memoized namespace version and thus forces a resynchonization of it.
      *
-     * @param bool $enable
-     *
      * @return bool the previous state of versioning
      */
-    public function enableVersioning($enable = true)
+    public function enableVersioning(bool $enable = true)
     {
         $wasEnabled = $this->versioningIsEnabled;
-        $this->versioningIsEnabled = (bool) $enable;
+        $this->versioningIsEnabled = $enable;
         $this->namespaceVersion = '';
         $this->ids = [];
 
@@ -356,7 +354,7 @@ private function generateItems(iterable $items, array &$keys): iterable
         }
     }
 
-    private function getId($key)
+    private function getId(string|int $key)
     {
         if ($this->versioningIsEnabled && '' === $this->namespaceVersion) {
             $this->ids = [];
diff --git a/src/Symfony/Component/Cache/Traits/MemcachedTrait.php b/src/Symfony/Component/Cache/Traits/MemcachedTrait.php
index 7b61e73a44727..ab6f8f41e7757 100644
--- a/src/Symfony/Component/Cache/Traits/MemcachedTrait.php
+++ b/src/Symfony/Component/Cache/Traits/MemcachedTrait.php
@@ -84,12 +84,10 @@ private function init(\Memcached $client, string $namespace, int $defaultLifetim
      *
      * @throws \ErrorException When invalid options or servers are provided
      */
-    public static function createConnection($servers, array $options = [])
+    public static function createConnection(string|array $servers, array $options = [])
     {
         if (\is_string($servers)) {
             $servers = [$servers];
-        } elseif (!\is_array($servers)) {
-            throw new InvalidArgumentException(sprintf('MemcachedAdapter::createClient() expects array or string as first argument, "%s" given.', \gettype($servers)));
         }
         if (!static::isSupported()) {
             throw new CacheException('Memcached >= 2.2.0 is required.');
@@ -273,7 +271,7 @@ protected function doFetch(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doHave($id)
+    protected function doHave(string $id)
     {
         return false !== $this->getClient()->get(self::encodeKey($id)) || $this->checkResultCode(\Memcached::RES_SUCCESS === $this->client->getResultCode());
     }
@@ -298,12 +296,12 @@ protected function doDelete(array $ids)
     /**
      * {@inheritdoc}
      */
-    protected function doClear($namespace)
+    protected function doClear(string $namespace)
     {
         return '' === $namespace && $this->getClient()->flush();
     }
 
-    private function checkResultCode($result)
+    private function checkResultCode(mixed $result)
     {
         $code = $this->client->getResultCode();
 
diff --git a/src/Symfony/Component/Cache/Traits/RedisTrait.php b/src/Symfony/Component/Cache/Traits/RedisTrait.php
index 618a2c3470007..8319d3ac4957c 100644
--- a/src/Symfony/Component/Cache/Traits/RedisTrait.php
+++ b/src/Symfony/Component/Cache/Traits/RedisTrait.php
@@ -47,10 +47,7 @@ trait RedisTrait
     private $redis;
     private $marshaller;
 
-    /**
-     * @param \Redis|\RedisArray|\RedisCluster|\Predis\ClientInterface $redisClient
-     */
-    private function init($redisClient, string $namespace, int $defaultLifetime, ?MarshallerInterface $marshaller)
+    private function init(\Redis|\RedisArray|\RedisCluster|\Predis\ClientInterface|RedisProxy|RedisClusterProxy $redisClient, string $namespace, int $defaultLifetime, ?MarshallerInterface $marshaller)
     {
         parent::__construct($namespace, $defaultLifetime);
 
@@ -58,10 +55,6 @@ private function init($redisClient, string $namespace, int $defaultLifetime, ?Ma
             throw new InvalidArgumentException(sprintf('RedisAdapter namespace contains "%s" but only characters in [-+_.A-Za-z0-9] are allowed.', $match[0]));
         }
 
-        if (!$redisClient instanceof \Redis && !$redisClient instanceof \RedisArray && !$redisClient instanceof \RedisCluster && !$redisClient instanceof \Predis\ClientInterface && !$redisClient instanceof RedisProxy && !$redisClient instanceof RedisClusterProxy) {
-            throw new InvalidArgumentException(sprintf('"%s()" expects parameter 1 to be Redis, RedisArray, RedisCluster or Predis\ClientInterface, "%s" given.', __METHOD__, get_debug_type($redisClient)));
-        }
-
         if ($redisClient instanceof \Predis\ClientInterface && $redisClient->getOptions()->exceptions) {
             $options = clone $redisClient->getOptions();
             \Closure::bind(function () { $this->options['exceptions'] = false; }, $options, $options)();
@@ -82,14 +75,13 @@ private function init($redisClient, string $namespace, int $defaultLifetime, ?Ma
      *   - redis:///var/run/redis.sock
      *   - redis://secret@/var/run/redis.sock/13
      *
-     * @param string $dsn
-     * @param array  $options See self::$defaultConnectionOptions
+     * @param array $options See self::$defaultConnectionOptions
      *
      * @throws InvalidArgumentException when the DSN is invalid
      *
      * @return \Redis|\RedisCluster|RedisClusterProxy|RedisProxy|\Predis\ClientInterface According to the "class" option
      */
-    public static function createConnection($dsn, array $options = [])
+    public static function createConnection(string $dsn, array $options = [])
     {
         if (0 === strpos($dsn, 'redis:')) {
             $scheme = 'redis';
@@ -498,7 +490,7 @@ protected function doSave(array $values, int $lifetime)
         return $failed;
     }
 
-    private function pipeline(\Closure $generator, $redis = null): \Generator
+    private function pipeline(\Closure $generator, object $redis = null): \Generator
     {
         $ids = [];
         $redis = $redis ?? $this->redis;