diff --git a/UPGRADE-4.3.md b/UPGRADE-4.3.md
index c2faae90c0b4d..981311492f1e3 100644
--- a/UPGRADE-4.3.md
+++ b/UPGRADE-4.3.md
@@ -8,6 +8,13 @@ BrowserKit
  * Deprecated `Response::buildHeader()`
  * Deprecated `Response::getStatus()`, use `Response::getStatusCode()` instead
 
+Cache
+-----
+
+ * The `psr/simple-cache` dependency has been removed - run `composer require psr/simple-cache` if you need it.
+ * Deprecated all PSR-16 adapters, use `Psr16Cache` or `Symfony\Contracts\Cache\CacheInterface` implementations instead.
+ * Deprecated `SimpleCacheAdapter`, use `Psr16Adapter instead.
+
 Config
 ------
 
@@ -18,6 +25,7 @@ FrameworkBundle
 
  * Not passing the project directory to the constructor of the `AssetsInstallCommand` is deprecated. This argument will
    be mandatory in 5.0.
+ * Deprecated the "Psr\SimpleCache\CacheInterface" / "cache.app.simple" service, use "Symfony\Contracts\Cache\CacheInterface" / "cache.app" instead.
 
 HttpFoundation
 --------------
diff --git a/UPGRADE-5.0.md b/UPGRADE-5.0.md
index 7e6703801bfb9..05669ffad31bb 100644
--- a/UPGRADE-5.0.md
+++ b/UPGRADE-5.0.md
@@ -13,6 +13,8 @@ Cache
 -----
 
  * Removed `CacheItem::getPreviousTags()`, use `CacheItem::getMetadata()` instead.
+ * Removed all PSR-16 adapters, use `Psr16Cache` or `Symfony\Contracts\Cache\CacheInterface` implementations instead.
+ * Removed `SimpleCacheAdapter`, use `Psr16Adapter instead.
 
 Config
 ------
@@ -163,6 +165,7 @@ FrameworkBundle
  * The `Templating\Helper\TranslatorHelper::transChoice()` method has been removed, use the `trans()` one instead with a `%count%` parameter.
  * Removed support for legacy translations directories `src/Resources/translations/` and `src/Resources/<BundleName>/translations/`, use `translations/` instead.
  * Support for the legacy directory structure in `translation:update` and `debug:translation` commands has been removed.
+ * Removed the "Psr\SimpleCache\CacheInterface" / "cache.app.simple" service, use "Symfony\Contracts\Cache\CacheInterface" / "cache.app" instead.
 
 HttpFoundation
 --------------
diff --git a/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md b/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
index 435fe4224d5e3..ec9f65711cb22 100644
--- a/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
+++ b/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
@@ -8,6 +8,7 @@ CHANGELOG
    be mandatory in 5.0.
  * Added `ControllerTrait::isFormValid()`
  * Added an `help_html` form option to display the `help` text as HTML
+ * Deprecated the "Psr\SimpleCache\CacheInterface" / "cache.app.simple" service, use "Symfony\Contracts\Cache\CacheInterface" / "cache.app" instead
 
  * [BC Break] When using Messenger, the default transport changed from
    using Symfony's serializer service to use `PhpSerializer`, which uses
diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/cache.xml b/src/Symfony/Bundle/FrameworkBundle/Resources/config/cache.xml
index 488cd868f3e32..753dee0e74e80 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/config/cache.xml
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/config/cache.xml
@@ -11,7 +11,8 @@
             <tag name="cache.pool" clearer="cache.app_clearer" reset="reset" />
         </service>
 
-        <service id="cache.app.simple" class="Symfony\Component\Cache\Simple\Psr6Cache">
+        <service id="cache.app.simple" class="Symfony\Component\Cache\Psr16Cache">
+            <deprecated>The "Psr\SimpleCache\CacheInterface" / "%service_id%" service is deprecated since Symfony 4.3. Use "Symfony\Contracts\Cache\CacheInterface" / "cache.app" instead.</deprecated>
             <argument type="service" id="cache.app" />
         </service>
 
diff --git a/src/Symfony/Bundle/FrameworkBundle/composer.json b/src/Symfony/Bundle/FrameworkBundle/composer.json
index 713a895e0e66c..de270782d9a07 100644
--- a/src/Symfony/Bundle/FrameworkBundle/composer.json
+++ b/src/Symfony/Bundle/FrameworkBundle/composer.json
@@ -18,7 +18,7 @@
     "require": {
         "php": "^7.1.3",
         "ext-xml": "*",
-        "symfony/cache": "~4.2",
+        "symfony/cache": "~4.3",
         "symfony/config": "~4.2",
         "symfony/contracts": "^1.0.2",
         "symfony/dependency-injection": "^4.2",
diff --git a/src/Symfony/Component/Cache/Adapter/Psr16Adapter.php b/src/Symfony/Component/Cache/Adapter/Psr16Adapter.php
new file mode 100644
index 0000000000000..a14ee082be1eb
--- /dev/null
+++ b/src/Symfony/Component/Cache/Adapter/Psr16Adapter.php
@@ -0,0 +1,81 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Adapter;
+
+use Psr\SimpleCache\CacheInterface;
+use Symfony\Component\Cache\PruneableInterface;
+use Symfony\Component\Cache\ResettableInterface;
+use Symfony\Component\Cache\Traits\ProxyTrait;
+
+/**
+ * Turns a PSR-16 cache into a PSR-6 one.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+class Psr16Adapter extends AbstractAdapter implements PruneableInterface, ResettableInterface
+{
+    use ProxyTrait;
+
+    private $miss;
+
+    public function __construct(CacheInterface $pool, string $namespace = '', int $defaultLifetime = 0)
+    {
+        parent::__construct($namespace, $defaultLifetime);
+
+        $this->pool = $pool;
+        $this->miss = new \stdClass();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doFetch(array $ids)
+    {
+        foreach ($this->pool->getMultiple($ids, $this->miss) as $key => $value) {
+            if ($this->miss !== $value) {
+                yield $key => $value;
+            }
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doHave($id)
+    {
+        return $this->pool->has($id);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doClear($namespace)
+    {
+        return $this->pool->clear();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doDelete(array $ids)
+    {
+        return $this->pool->deleteMultiple($ids);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doSave(array $values, $lifetime)
+    {
+        return $this->pool->setMultiple($values, 0 === $lifetime ? null : $lifetime);
+    }
+}
diff --git a/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php b/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php
index 2e6d03a1f0b41..d0d42e57f0a7c 100644
--- a/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php
@@ -11,69 +11,11 @@
 
 namespace Symfony\Component\Cache\Adapter;
 
-use Psr\SimpleCache\CacheInterface;
-use Symfony\Component\Cache\PruneableInterface;
-use Symfony\Component\Cache\ResettableInterface;
-use Symfony\Component\Cache\Traits\ProxyTrait;
+@trigger_error(sprintf('The "%s" class is @deprecated since Symfony 4.3, use "Psr16Adapter" instead.', SimpleCacheAdapter::class), E_USER_DEPRECATED);
 
 /**
- * @author Nicolas Grekas <p@tchwork.com>
+ * @deprecated since Symfony 4.3, use Psr16Adapter instead.
  */
-class SimpleCacheAdapter extends AbstractAdapter implements PruneableInterface, ResettableInterface
+class SimpleCacheAdapter extends Psr16Adapter
 {
-    use ProxyTrait;
-
-    private $miss;
-
-    public function __construct(CacheInterface $pool, string $namespace = '', int $defaultLifetime = 0)
-    {
-        parent::__construct($namespace, $defaultLifetime);
-
-        $this->pool = $pool;
-        $this->miss = new \stdClass();
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    protected function doFetch(array $ids)
-    {
-        foreach ($this->pool->getMultiple($ids, $this->miss) as $key => $value) {
-            if ($this->miss !== $value) {
-                yield $key => $value;
-            }
-        }
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    protected function doHave($id)
-    {
-        return $this->pool->has($id);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    protected function doClear($namespace)
-    {
-        return $this->pool->clear();
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    protected function doDelete(array $ids)
-    {
-        return $this->pool->deleteMultiple($ids);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    protected function doSave(array $values, $lifetime)
-    {
-        return $this->pool->setMultiple($values, 0 === $lifetime ? null : $lifetime);
-    }
 }
diff --git a/src/Symfony/Component/Cache/CHANGELOG.md b/src/Symfony/Component/Cache/CHANGELOG.md
index 9016bc5dbfe2e..37dd2e11a0e61 100644
--- a/src/Symfony/Component/Cache/CHANGELOG.md
+++ b/src/Symfony/Component/Cache/CHANGELOG.md
@@ -1,6 +1,13 @@
 CHANGELOG
 =========
 
+4.3.0
+-----
+
+ * removed `psr/simple-cache` dependency, run `composer require psr/simple-cache` if you need it
+ * deprecated all PSR-16 adapters, use `Psr16Cache` or `Symfony\Contracts\Cache\CacheInterface` implementations instead
+ * deprecated `SimpleCacheAdapter`, use `Psr16Adapter` instead
+
 4.2.0
 -----
 
diff --git a/src/Symfony/Component/Cache/Exception/CacheException.php b/src/Symfony/Component/Cache/Exception/CacheException.php
index e87b2db8fe733..d2e975b2bc606 100644
--- a/src/Symfony/Component/Cache/Exception/CacheException.php
+++ b/src/Symfony/Component/Cache/Exception/CacheException.php
@@ -14,6 +14,12 @@
 use Psr\Cache\CacheException as Psr6CacheInterface;
 use Psr\SimpleCache\CacheException as SimpleCacheInterface;
 
-class CacheException extends \Exception implements Psr6CacheInterface, SimpleCacheInterface
-{
+if (interface_exists(SimpleCacheInterface::class)) {
+    class CacheException extends \Exception implements Psr6CacheInterface, SimpleCacheInterface
+    {
+    }
+} else {
+    class CacheException extends \Exception implements Psr6CacheInterface
+    {
+    }
 }
diff --git a/src/Symfony/Component/Cache/Exception/InvalidArgumentException.php b/src/Symfony/Component/Cache/Exception/InvalidArgumentException.php
index 828bf3ed77999..7f9584a264328 100644
--- a/src/Symfony/Component/Cache/Exception/InvalidArgumentException.php
+++ b/src/Symfony/Component/Cache/Exception/InvalidArgumentException.php
@@ -14,6 +14,12 @@
 use Psr\Cache\InvalidArgumentException as Psr6CacheInterface;
 use Psr\SimpleCache\InvalidArgumentException as SimpleCacheInterface;
 
-class InvalidArgumentException extends \InvalidArgumentException implements Psr6CacheInterface, SimpleCacheInterface
-{
+if (interface_exists(SimpleCacheInterface::class)) {
+    class InvalidArgumentException extends \InvalidArgumentException implements Psr6CacheInterface, SimpleCacheInterface
+    {
+    }
+} else {
+    class InvalidArgumentException extends \InvalidArgumentException implements Psr6CacheInterface
+    {
+    }
 }
diff --git a/src/Symfony/Component/Cache/Exception/LogicException.php b/src/Symfony/Component/Cache/Exception/LogicException.php
index d299673eb2246..9ffa7ed69566b 100644
--- a/src/Symfony/Component/Cache/Exception/LogicException.php
+++ b/src/Symfony/Component/Cache/Exception/LogicException.php
@@ -14,6 +14,12 @@
 use Psr\Cache\CacheException as Psr6CacheInterface;
 use Psr\SimpleCache\CacheException as SimpleCacheInterface;
 
-class LogicException extends \LogicException implements Psr6CacheInterface, SimpleCacheInterface
-{
+if (interface_exists(SimpleCacheInterface::class)) {
+    class LogicException extends \LogicException implements Psr6CacheInterface, SimpleCacheInterface
+    {
+    }
+} else {
+    class LogicException extends \LogicException implements Psr6CacheInterface
+    {
+    }
 }
diff --git a/src/Symfony/Component/Cache/LockRegistry.php b/src/Symfony/Component/Cache/LockRegistry.php
index e0318e900c4d5..3fa8bb851237c 100644
--- a/src/Symfony/Component/Cache/LockRegistry.php
+++ b/src/Symfony/Component/Cache/LockRegistry.php
@@ -45,6 +45,7 @@ class LockRegistry
         __DIR__.\DIRECTORY_SEPARATOR.'Adapter'.\DIRECTORY_SEPARATOR.'PhpArrayAdapter.php',
         __DIR__.\DIRECTORY_SEPARATOR.'Adapter'.\DIRECTORY_SEPARATOR.'PhpFilesAdapter.php',
         __DIR__.\DIRECTORY_SEPARATOR.'Adapter'.\DIRECTORY_SEPARATOR.'ProxyAdapter.php',
+        __DIR__.\DIRECTORY_SEPARATOR.'Adapter'.\DIRECTORY_SEPARATOR.'Psr16Adapter.php',
         __DIR__.\DIRECTORY_SEPARATOR.'Adapter'.\DIRECTORY_SEPARATOR.'RedisAdapter.php',
         __DIR__.\DIRECTORY_SEPARATOR.'Adapter'.\DIRECTORY_SEPARATOR.'SimpleCacheAdapter.php',
         __DIR__.\DIRECTORY_SEPARATOR.'Adapter'.\DIRECTORY_SEPARATOR.'TagAwareAdapter.php',
diff --git a/src/Symfony/Component/Cache/Psr16Cache.php b/src/Symfony/Component/Cache/Psr16Cache.php
new file mode 100644
index 0000000000000..589ffa0d8b7b8
--- /dev/null
+++ b/src/Symfony/Component/Cache/Psr16Cache.php
@@ -0,0 +1,263 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache;
+
+use Psr\Cache\CacheException as Psr6CacheException;
+use Psr\Cache\CacheItemPoolInterface;
+use Psr\SimpleCache\CacheException as SimpleCacheException;
+use Psr\SimpleCache\CacheInterface;
+use Symfony\Component\Cache\Adapter\AdapterInterface;
+use Symfony\Component\Cache\Exception\InvalidArgumentException;
+use Symfony\Component\Cache\Traits\ProxyTrait;
+
+/**
+ * Turns a PSR-6 cache into a PSR-16 one.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+class Psr16Cache implements CacheInterface, PruneableInterface, ResettableInterface
+{
+    use ProxyTrait;
+
+    private const METADATA_EXPIRY_OFFSET = 1527506807;
+
+    private $createCacheItem;
+    private $cacheItemPrototype;
+
+    public function __construct(CacheItemPoolInterface $pool)
+    {
+        $this->pool = $pool;
+
+        if (!$pool instanceof AdapterInterface) {
+            return;
+        }
+        $cacheItemPrototype = &$this->cacheItemPrototype;
+        $createCacheItem = \Closure::bind(
+            function ($key, $value, $allowInt = false) use (&$cacheItemPrototype) {
+                $item = clone $cacheItemPrototype;
+                $item->key = $allowInt && \is_int($key) ? (string) $key : CacheItem::validateKey($key);
+                $item->value = $value;
+                $item->isHit = false;
+
+                return $item;
+            },
+            null,
+            CacheItem::class
+        );
+        $this->createCacheItem = function ($key, $value, $allowInt = false) use ($createCacheItem) {
+            if (null === $this->cacheItemPrototype) {
+                $this->get($allowInt && \is_int($key) ? (string) $key : $key);
+            }
+            $this->createCacheItem = $createCacheItem;
+
+            return $createCacheItem($key, null, $allowInt)->set($value);
+        };
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function get($key, $default = null)
+    {
+        try {
+            $item = $this->pool->getItem($key);
+        } catch (SimpleCacheException $e) {
+            throw $e;
+        } catch (Psr6CacheException $e) {
+            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
+        }
+        if (null === $this->cacheItemPrototype) {
+            $this->cacheItemPrototype = clone $item;
+            $this->cacheItemPrototype->set(null);
+        }
+
+        return $item->isHit() ? $item->get() : $default;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function set($key, $value, $ttl = null)
+    {
+        try {
+            if (null !== $f = $this->createCacheItem) {
+                $item = $f($key, $value);
+            } else {
+                $item = $this->pool->getItem($key)->set($value);
+            }
+        } catch (SimpleCacheException $e) {
+            throw $e;
+        } catch (Psr6CacheException $e) {
+            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
+        }
+        if (null !== $ttl) {
+            $item->expiresAfter($ttl);
+        }
+
+        return $this->pool->save($item);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function delete($key)
+    {
+        try {
+            return $this->pool->deleteItem($key);
+        } catch (SimpleCacheException $e) {
+            throw $e;
+        } catch (Psr6CacheException $e) {
+            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function clear()
+    {
+        return $this->pool->clear();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getMultiple($keys, $default = null)
+    {
+        if ($keys instanceof \Traversable) {
+            $keys = iterator_to_array($keys, false);
+        } elseif (!\is_array($keys)) {
+            throw new InvalidArgumentException(sprintf('Cache keys must be array or Traversable, "%s" given', \is_object($keys) ? \get_class($keys) : \gettype($keys)));
+        }
+
+        try {
+            $items = $this->pool->getItems($keys);
+        } catch (SimpleCacheException $e) {
+            throw $e;
+        } catch (Psr6CacheException $e) {
+            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
+        }
+        $values = [];
+
+        if (!$this->pool instanceof AdapterInterface) {
+            foreach ($items as $key => $item) {
+                $values[$key] = $item->isHit() ? $item->get() : $default;
+            }
+
+            return $values;
+        }
+
+        foreach ($items as $key => $item) {
+            if (!$item->isHit()) {
+                $values[$key] = $default;
+                continue;
+            }
+            $values[$key] = $item->get();
+
+            if (!$metadata = $item->getMetadata()) {
+                continue;
+            }
+            unset($metadata[CacheItem::METADATA_TAGS]);
+
+            if ($metadata) {
+                $values[$key] = ["\x9D".pack('VN', (int) $metadata[CacheItem::METADATA_EXPIRY] - self::METADATA_EXPIRY_OFFSET, $metadata[CacheItem::METADATA_CTIME])."\x5F" => $values[$key]];
+            }
+        }
+
+        return $values;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function setMultiple($values, $ttl = null)
+    {
+        $valuesIsArray = \is_array($values);
+        if (!$valuesIsArray && !$values instanceof \Traversable) {
+            throw new InvalidArgumentException(sprintf('Cache values must be array or Traversable, "%s" given', \is_object($values) ? \get_class($values) : \gettype($values)));
+        }
+        $items = [];
+
+        try {
+            if (null !== $f = $this->createCacheItem) {
+                $valuesIsArray = false;
+                foreach ($values as $key => $value) {
+                    $items[$key] = $f($key, $value, true);
+                }
+            } elseif ($valuesIsArray) {
+                $items = [];
+                foreach ($values as $key => $value) {
+                    $items[] = (string) $key;
+                }
+                $items = $this->pool->getItems($items);
+            } else {
+                foreach ($values as $key => $value) {
+                    if (\is_int($key)) {
+                        $key = (string) $key;
+                    }
+                    $items[$key] = $this->pool->getItem($key)->set($value);
+                }
+            }
+        } catch (SimpleCacheException $e) {
+            throw $e;
+        } catch (Psr6CacheException $e) {
+            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
+        }
+        $ok = true;
+
+        foreach ($items as $key => $item) {
+            if ($valuesIsArray) {
+                $item->set($values[$key]);
+            }
+            if (null !== $ttl) {
+                $item->expiresAfter($ttl);
+            }
+            $ok = $this->pool->saveDeferred($item) && $ok;
+        }
+
+        return $this->pool->commit() && $ok;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function deleteMultiple($keys)
+    {
+        if ($keys instanceof \Traversable) {
+            $keys = iterator_to_array($keys, false);
+        } elseif (!\is_array($keys)) {
+            throw new InvalidArgumentException(sprintf('Cache keys must be array or Traversable, "%s" given', \is_object($keys) ? \get_class($keys) : \gettype($keys)));
+        }
+
+        try {
+            return $this->pool->deleteItems($keys);
+        } catch (SimpleCacheException $e) {
+            throw $e;
+        } catch (Psr6CacheException $e) {
+            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function has($key)
+    {
+        try {
+            return $this->pool->hasItem($key);
+        } catch (SimpleCacheException $e) {
+            throw $e;
+        } catch (Psr6CacheException $e) {
+            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
+        }
+    }
+}
diff --git a/src/Symfony/Component/Cache/Simple/AbstractCache.php b/src/Symfony/Component/Cache/Simple/AbstractCache.php
index 7a2a3cb36e996..29fbd7719ecb8 100644
--- a/src/Symfony/Component/Cache/Simple/AbstractCache.php
+++ b/src/Symfony/Component/Cache/Simple/AbstractCache.php
@@ -12,16 +12,20 @@
 namespace Symfony\Component\Cache\Simple;
 
 use Psr\Log\LoggerAwareInterface;
-use Psr\SimpleCache\CacheInterface;
+use Psr\SimpleCache\CacheInterface as Psr16CacheInterface;
+use Symfony\Component\Cache\Adapter\AbstractAdapter;
 use Symfony\Component\Cache\CacheItem;
 use Symfony\Component\Cache\Exception\InvalidArgumentException;
 use Symfony\Component\Cache\ResettableInterface;
 use Symfony\Component\Cache\Traits\AbstractTrait;
+use Symfony\Contracts\Cache\CacheInterface;
+
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', AbstractCache::class, AbstractAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
 
 /**
- * @author Nicolas Grekas <p@tchwork.com>
+ * @deprecated since Symfony 4.3, use AbstractAdapter and type-hint for CacheInterface instead.
  */
-abstract class AbstractCache implements CacheInterface, LoggerAwareInterface, ResettableInterface
+abstract class AbstractCache implements Psr16CacheInterface, LoggerAwareInterface, ResettableInterface
 {
     use AbstractTrait {
         deleteItems as private;
diff --git a/src/Symfony/Component/Cache/Simple/ApcuCache.php b/src/Symfony/Component/Cache/Simple/ApcuCache.php
index 0877c394bbda3..c22771e8227c5 100644
--- a/src/Symfony/Component/Cache/Simple/ApcuCache.php
+++ b/src/Symfony/Component/Cache/Simple/ApcuCache.php
@@ -13,6 +13,11 @@
 
 use Symfony\Component\Cache\Traits\ApcuTrait;
 
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', ApcuCache::class, ApcuAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
+
+/**
+ * @deprecated since Symfony 4.3, use ApcuAdapter and type-hint for CacheInterface instead.
+ */
 class ApcuCache extends AbstractCache
 {
     use ApcuTrait;
diff --git a/src/Symfony/Component/Cache/Simple/ArrayCache.php b/src/Symfony/Component/Cache/Simple/ArrayCache.php
index e36dacb829470..3df5b4990c241 100644
--- a/src/Symfony/Component/Cache/Simple/ArrayCache.php
+++ b/src/Symfony/Component/Cache/Simple/ArrayCache.php
@@ -12,16 +12,20 @@
 namespace Symfony\Component\Cache\Simple;
 
 use Psr\Log\LoggerAwareInterface;
-use Psr\SimpleCache\CacheInterface;
+use Psr\SimpleCache\CacheInterface as Psr16CacheInterface;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
 use Symfony\Component\Cache\CacheItem;
 use Symfony\Component\Cache\Exception\InvalidArgumentException;
 use Symfony\Component\Cache\ResettableInterface;
 use Symfony\Component\Cache\Traits\ArrayTrait;
+use Symfony\Contracts\Cache\CacheInterface;
+
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', ArrayCache::class, ArrayAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
 
 /**
- * @author Nicolas Grekas <p@tchwork.com>
+ * @deprecated since Symfony 4.3, use ArrayAdapter and type-hint for CacheInterface instead.
  */
-class ArrayCache implements CacheInterface, LoggerAwareInterface, ResettableInterface
+class ArrayCache implements Psr16CacheInterface, LoggerAwareInterface, ResettableInterface
 {
     use ArrayTrait {
         ArrayTrait::deleteItem as delete;
diff --git a/src/Symfony/Component/Cache/Simple/ChainCache.php b/src/Symfony/Component/Cache/Simple/ChainCache.php
index 18e9462ba02ad..a0122fdee9292 100644
--- a/src/Symfony/Component/Cache/Simple/ChainCache.php
+++ b/src/Symfony/Component/Cache/Simple/ChainCache.php
@@ -11,21 +11,25 @@
 
 namespace Symfony\Component\Cache\Simple;
 
-use Psr\SimpleCache\CacheInterface;
+use Psr\SimpleCache\CacheInterface as Psr16CacheInterface;
+use Symfony\Component\Cache\Adapter\ChainAdapter;
 use Symfony\Component\Cache\Exception\InvalidArgumentException;
 use Symfony\Component\Cache\PruneableInterface;
 use Symfony\Component\Cache\ResettableInterface;
+use Symfony\Contracts\Cache\CacheInterface;
 use Symfony\Contracts\Service\ResetInterface;
 
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', ChainCache::class, ChainAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
+
 /**
  * Chains several caches together.
  *
  * Cached items are fetched from the first cache having them in its data store.
  * They are saved and deleted in all caches at once.
  *
- * @author Nicolas Grekas <p@tchwork.com>
+ * @deprecated since Symfony 4.3, use ChainAdapter and type-hint for CacheInterface instead.
  */
-class ChainCache implements CacheInterface, PruneableInterface, ResettableInterface
+class ChainCache implements Psr16CacheInterface, PruneableInterface, ResettableInterface
 {
     private $miss;
     private $caches = [];
@@ -33,8 +37,8 @@ class ChainCache implements CacheInterface, PruneableInterface, ResettableInterf
     private $cacheCount;
 
     /**
-     * @param CacheInterface[] $caches          The ordered list of caches used to fetch cached items
-     * @param int              $defaultLifetime The lifetime of items propagated from lower caches to upper ones
+     * @param Psr16CacheInterface[] $caches          The ordered list of caches used to fetch cached items
+     * @param int                   $defaultLifetime The lifetime of items propagated from lower caches to upper ones
      */
     public function __construct(array $caches, int $defaultLifetime = 0)
     {
@@ -43,8 +47,8 @@ public function __construct(array $caches, int $defaultLifetime = 0)
         }
 
         foreach ($caches as $cache) {
-            if (!$cache instanceof CacheInterface) {
-                throw new InvalidArgumentException(sprintf('The class "%s" does not implement the "%s" interface.', \get_class($cache), CacheInterface::class));
+            if (!$cache instanceof Psr16CacheInterface) {
+                throw new InvalidArgumentException(sprintf('The class "%s" does not implement the "%s" interface.', \get_class($cache), Psr16CacheInterface::class));
             }
         }
 
diff --git a/src/Symfony/Component/Cache/Simple/DoctrineCache.php b/src/Symfony/Component/Cache/Simple/DoctrineCache.php
index 0ba701d7cd9a6..6a6d0031533e8 100644
--- a/src/Symfony/Component/Cache/Simple/DoctrineCache.php
+++ b/src/Symfony/Component/Cache/Simple/DoctrineCache.php
@@ -12,8 +12,15 @@
 namespace Symfony\Component\Cache\Simple;
 
 use Doctrine\Common\Cache\CacheProvider;
+use Symfony\Component\Cache\Adapter\DoctrineAdapter;
 use Symfony\Component\Cache\Traits\DoctrineTrait;
+use Symfony\Contracts\Cache\CacheInterface;
 
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', DoctrineCache::class, DoctrineAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
+
+/**
+ * @deprecated since Symfony 4.3, use DoctrineAdapter and type-hint for CacheInterface instead.
+ */
 class DoctrineCache extends AbstractCache
 {
     use DoctrineTrait;
diff --git a/src/Symfony/Component/Cache/Simple/FilesystemCache.php b/src/Symfony/Component/Cache/Simple/FilesystemCache.php
index 8e04d533556ef..8891abd94c9fe 100644
--- a/src/Symfony/Component/Cache/Simple/FilesystemCache.php
+++ b/src/Symfony/Component/Cache/Simple/FilesystemCache.php
@@ -11,11 +11,18 @@
 
 namespace Symfony\Component\Cache\Simple;
 
+use Symfony\Component\Cache\Adapter\FilesystemAdapter;
 use Symfony\Component\Cache\Marshaller\DefaultMarshaller;
 use Symfony\Component\Cache\Marshaller\MarshallerInterface;
 use Symfony\Component\Cache\PruneableInterface;
 use Symfony\Component\Cache\Traits\FilesystemTrait;
+use Symfony\Contracts\Cache\CacheInterface;
 
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', FilesystemCache::class, FilesystemAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
+
+/**
+ * @deprecated since Symfony 4.3, use FilesystemAdapter and type-hint for CacheInterface instead.
+ */
 class FilesystemCache extends AbstractCache implements PruneableInterface
 {
     use FilesystemTrait;
diff --git a/src/Symfony/Component/Cache/Simple/MemcachedCache.php b/src/Symfony/Component/Cache/Simple/MemcachedCache.php
index 8e418b071e632..e1934119aa74a 100644
--- a/src/Symfony/Component/Cache/Simple/MemcachedCache.php
+++ b/src/Symfony/Component/Cache/Simple/MemcachedCache.php
@@ -11,9 +11,16 @@
 
 namespace Symfony\Component\Cache\Simple;
 
+use Symfony\Component\Cache\Adapter\MemcachedAdapter;
 use Symfony\Component\Cache\Marshaller\MarshallerInterface;
 use Symfony\Component\Cache\Traits\MemcachedTrait;
+use Symfony\Contracts\Cache\CacheInterface;
 
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', MemcachedCache::class, MemcachedAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
+
+/**
+ * @deprecated since Symfony 4.3, use MemcachedAdapter and type-hint for CacheInterface instead.
+ */
 class MemcachedCache extends AbstractCache
 {
     use MemcachedTrait;
diff --git a/src/Symfony/Component/Cache/Simple/NullCache.php b/src/Symfony/Component/Cache/Simple/NullCache.php
index fa986aebd11b0..d1ca6f71873b0 100644
--- a/src/Symfony/Component/Cache/Simple/NullCache.php
+++ b/src/Symfony/Component/Cache/Simple/NullCache.php
@@ -11,12 +11,16 @@
 
 namespace Symfony\Component\Cache\Simple;
 
-use Psr\SimpleCache\CacheInterface;
+use Psr\SimpleCache\CacheInterface as Psr16CacheInterface;
+use Symfony\Components\Cache\Adapter\NullAdapter;
+use Symfony\Contracts\Cache\CacheInterface;
+
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', NullCache::class, NullAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
 
 /**
- * @author Nicolas Grekas <p@tchwork.com>
+ * @deprecated since Symfony 4.3, use NullAdapter and type-hint for CacheInterface instead.
  */
-class NullCache implements CacheInterface
+class NullCache implements Psr16CacheInterface
 {
     /**
      * {@inheritdoc}
diff --git a/src/Symfony/Component/Cache/Simple/PdoCache.php b/src/Symfony/Component/Cache/Simple/PdoCache.php
index 521e9b8f2d7f5..07849e93feb9a 100644
--- a/src/Symfony/Component/Cache/Simple/PdoCache.php
+++ b/src/Symfony/Component/Cache/Simple/PdoCache.php
@@ -11,10 +11,17 @@
 
 namespace Symfony\Component\Cache\Simple;
 
+use Symfony\Component\Cache\Adapter\PdoAdapter;
 use Symfony\Component\Cache\Marshaller\MarshallerInterface;
 use Symfony\Component\Cache\PruneableInterface;
 use Symfony\Component\Cache\Traits\PdoTrait;
+use Symfony\Contracts\Cache\CacheInterface;
 
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', PdoCache::class, PdoAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
+
+/**
+ * @deprecated since Symfony 4.3, use PdoAdapter and type-hint for CacheInterface instead.
+ */
 class PdoCache extends AbstractCache implements PruneableInterface
 {
     use PdoTrait;
diff --git a/src/Symfony/Component/Cache/Simple/PhpArrayCache.php b/src/Symfony/Component/Cache/Simple/PhpArrayCache.php
index 6ba8527885e32..566609359d568 100644
--- a/src/Symfony/Component/Cache/Simple/PhpArrayCache.php
+++ b/src/Symfony/Component/Cache/Simple/PhpArrayCache.php
@@ -11,28 +11,28 @@
 
 namespace Symfony\Component\Cache\Simple;
 
-use Psr\SimpleCache\CacheInterface;
+use Psr\SimpleCache\CacheInterface as Psr16CacheInterface;
+use Symfony\Component\Cache\Adapter\PhpArrayAdapter;
 use Symfony\Component\Cache\Exception\InvalidArgumentException;
 use Symfony\Component\Cache\PruneableInterface;
 use Symfony\Component\Cache\ResettableInterface;
 use Symfony\Component\Cache\Traits\PhpArrayTrait;
+use Symfony\Contracts\Cache\CacheInterface;
+
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', PhpArrayCache::class, PhpArrayAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
 
 /**
- * Caches items at warm up time using a PHP array that is stored in shared memory by OPCache since PHP 7.0.
- * Warmed up items are read-only and run-time discovered items are cached using a fallback adapter.
- *
- * @author Titouan Galopin <galopintitouan@gmail.com>
- * @author Nicolas Grekas <p@tchwork.com>
+ * @deprecated since Symfony 4.3, use PhpArrayAdapter and type-hint for CacheInterface instead.
  */
-class PhpArrayCache implements CacheInterface, PruneableInterface, ResettableInterface
+class PhpArrayCache implements Psr16CacheInterface, PruneableInterface, ResettableInterface
 {
     use PhpArrayTrait;
 
     /**
-     * @param string         $file         The PHP file were values are cached
-     * @param CacheInterface $fallbackPool A pool to fallback on when an item is not hit
+     * @param string              $file         The PHP file were values are cached
+     * @param Psr16CacheInterface $fallbackPool A pool to fallback on when an item is not hit
      */
-    public function __construct(string $file, CacheInterface $fallbackPool)
+    public function __construct(string $file, Psr16CacheInterface $fallbackPool)
     {
         $this->file = $file;
         $this->pool = $fallbackPool;
@@ -43,9 +43,9 @@ public function __construct(string $file, CacheInterface $fallbackPool)
      *
      * @param string $file The PHP file were values are cached
      *
-     * @return CacheInterface
+     * @return Psr16CacheInterface
      */
-    public static function create($file, CacheInterface $fallbackPool)
+    public static function create($file, Psr16CacheInterface $fallbackPool)
     {
         // Shared memory is available in PHP 7.0+ with OPCache enabled
         if (filter_var(ini_get('opcache.enable'), FILTER_VALIDATE_BOOLEAN)) {
diff --git a/src/Symfony/Component/Cache/Simple/PhpFilesCache.php b/src/Symfony/Component/Cache/Simple/PhpFilesCache.php
index 37432c5af8e4b..060244a086643 100644
--- a/src/Symfony/Component/Cache/Simple/PhpFilesCache.php
+++ b/src/Symfony/Component/Cache/Simple/PhpFilesCache.php
@@ -11,10 +11,17 @@
 
 namespace Symfony\Component\Cache\Simple;
 
+use Symfony\Component\Cache\Adapter\PhpFilesAdapter;
 use Symfony\Component\Cache\Exception\CacheException;
 use Symfony\Component\Cache\PruneableInterface;
 use Symfony\Component\Cache\Traits\PhpFilesTrait;
+use Symfony\Contracts\Cache\CacheInterface;
 
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', PhpFilesCache::class, PhpFilesAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
+
+/**
+ * @deprecated since Symfony 4.3, use PhpFilesAdapter and type-hint for CacheInterface instead.
+ */
 class PhpFilesCache extends AbstractCache implements PruneableInterface
 {
     use PhpFilesTrait;
diff --git a/src/Symfony/Component/Cache/Simple/Psr6Cache.php b/src/Symfony/Component/Cache/Simple/Psr6Cache.php
index fceb9ba70fd80..090f48c172860 100644
--- a/src/Symfony/Component/Cache/Simple/Psr6Cache.php
+++ b/src/Symfony/Component/Cache/Simple/Psr6Cache.php
@@ -11,254 +11,13 @@
 
 namespace Symfony\Component\Cache\Simple;
 
-use Psr\Cache\CacheException as Psr6CacheException;
-use Psr\Cache\CacheItemPoolInterface;
-use Psr\SimpleCache\CacheException as SimpleCacheException;
-use Psr\SimpleCache\CacheInterface;
-use Symfony\Component\Cache\Adapter\AdapterInterface;
-use Symfony\Component\Cache\CacheItem;
-use Symfony\Component\Cache\Exception\InvalidArgumentException;
-use Symfony\Component\Cache\PruneableInterface;
-use Symfony\Component\Cache\ResettableInterface;
-use Symfony\Component\Cache\Traits\ProxyTrait;
+use Symfony\Component\Cache\Psr16Cache;
+
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" instead.', Psr6Cache::class, Psr16Cache::class), E_USER_DEPRECATED);
 
 /**
- * @author Nicolas Grekas <p@tchwork.com>
+ * @deprecated since Symfony 4.3, use Psr16Cache instead.
  */
-class Psr6Cache implements CacheInterface, PruneableInterface, ResettableInterface
+class Psr6Cache extends Psr16Cache
 {
-    use ProxyTrait;
-
-    private const METADATA_EXPIRY_OFFSET = 1527506807;
-
-    private $createCacheItem;
-    private $cacheItemPrototype;
-
-    public function __construct(CacheItemPoolInterface $pool)
-    {
-        $this->pool = $pool;
-
-        if (!$pool instanceof AdapterInterface) {
-            return;
-        }
-        $cacheItemPrototype = &$this->cacheItemPrototype;
-        $createCacheItem = \Closure::bind(
-            function ($key, $value, $allowInt = false) use (&$cacheItemPrototype) {
-                $item = clone $cacheItemPrototype;
-                $item->key = $allowInt && \is_int($key) ? (string) $key : CacheItem::validateKey($key);
-                $item->value = $value;
-                $item->isHit = false;
-
-                return $item;
-            },
-            null,
-            CacheItem::class
-        );
-        $this->createCacheItem = function ($key, $value, $allowInt = false) use ($createCacheItem) {
-            if (null === $this->cacheItemPrototype) {
-                $this->get($allowInt && \is_int($key) ? (string) $key : $key);
-            }
-            $this->createCacheItem = $createCacheItem;
-
-            return $createCacheItem($key, null, $allowInt)->set($value);
-        };
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function get($key, $default = null)
-    {
-        try {
-            $item = $this->pool->getItem($key);
-        } catch (SimpleCacheException $e) {
-            throw $e;
-        } catch (Psr6CacheException $e) {
-            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
-        }
-        if (null === $this->cacheItemPrototype) {
-            $this->cacheItemPrototype = clone $item;
-            $this->cacheItemPrototype->set(null);
-        }
-
-        return $item->isHit() ? $item->get() : $default;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function set($key, $value, $ttl = null)
-    {
-        try {
-            if (null !== $f = $this->createCacheItem) {
-                $item = $f($key, $value);
-            } else {
-                $item = $this->pool->getItem($key)->set($value);
-            }
-        } catch (SimpleCacheException $e) {
-            throw $e;
-        } catch (Psr6CacheException $e) {
-            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
-        }
-        if (null !== $ttl) {
-            $item->expiresAfter($ttl);
-        }
-
-        return $this->pool->save($item);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function delete($key)
-    {
-        try {
-            return $this->pool->deleteItem($key);
-        } catch (SimpleCacheException $e) {
-            throw $e;
-        } catch (Psr6CacheException $e) {
-            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
-        }
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function clear()
-    {
-        return $this->pool->clear();
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getMultiple($keys, $default = null)
-    {
-        if ($keys instanceof \Traversable) {
-            $keys = iterator_to_array($keys, false);
-        } elseif (!\is_array($keys)) {
-            throw new InvalidArgumentException(sprintf('Cache keys must be array or Traversable, "%s" given', \is_object($keys) ? \get_class($keys) : \gettype($keys)));
-        }
-
-        try {
-            $items = $this->pool->getItems($keys);
-        } catch (SimpleCacheException $e) {
-            throw $e;
-        } catch (Psr6CacheException $e) {
-            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
-        }
-        $values = [];
-
-        if (!$this->pool instanceof AdapterInterface) {
-            foreach ($items as $key => $item) {
-                $values[$key] = $item->isHit() ? $item->get() : $default;
-            }
-
-            return $values;
-        }
-
-        foreach ($items as $key => $item) {
-            if (!$item->isHit()) {
-                $values[$key] = $default;
-                continue;
-            }
-            $values[$key] = $item->get();
-
-            if (!$metadata = $item->getMetadata()) {
-                continue;
-            }
-            unset($metadata[CacheItem::METADATA_TAGS]);
-
-            if ($metadata) {
-                $values[$key] = ["\x9D".pack('VN', (int) $metadata[CacheItem::METADATA_EXPIRY] - self::METADATA_EXPIRY_OFFSET, $metadata[CacheItem::METADATA_CTIME])."\x5F" => $values[$key]];
-            }
-        }
-
-        return $values;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function setMultiple($values, $ttl = null)
-    {
-        $valuesIsArray = \is_array($values);
-        if (!$valuesIsArray && !$values instanceof \Traversable) {
-            throw new InvalidArgumentException(sprintf('Cache values must be array or Traversable, "%s" given', \is_object($values) ? \get_class($values) : \gettype($values)));
-        }
-        $items = [];
-
-        try {
-            if (null !== $f = $this->createCacheItem) {
-                $valuesIsArray = false;
-                foreach ($values as $key => $value) {
-                    $items[$key] = $f($key, $value, true);
-                }
-            } elseif ($valuesIsArray) {
-                $items = [];
-                foreach ($values as $key => $value) {
-                    $items[] = (string) $key;
-                }
-                $items = $this->pool->getItems($items);
-            } else {
-                foreach ($values as $key => $value) {
-                    if (\is_int($key)) {
-                        $key = (string) $key;
-                    }
-                    $items[$key] = $this->pool->getItem($key)->set($value);
-                }
-            }
-        } catch (SimpleCacheException $e) {
-            throw $e;
-        } catch (Psr6CacheException $e) {
-            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
-        }
-        $ok = true;
-
-        foreach ($items as $key => $item) {
-            if ($valuesIsArray) {
-                $item->set($values[$key]);
-            }
-            if (null !== $ttl) {
-                $item->expiresAfter($ttl);
-            }
-            $ok = $this->pool->saveDeferred($item) && $ok;
-        }
-
-        return $this->pool->commit() && $ok;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function deleteMultiple($keys)
-    {
-        if ($keys instanceof \Traversable) {
-            $keys = iterator_to_array($keys, false);
-        } elseif (!\is_array($keys)) {
-            throw new InvalidArgumentException(sprintf('Cache keys must be array or Traversable, "%s" given', \is_object($keys) ? \get_class($keys) : \gettype($keys)));
-        }
-
-        try {
-            return $this->pool->deleteItems($keys);
-        } catch (SimpleCacheException $e) {
-            throw $e;
-        } catch (Psr6CacheException $e) {
-            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
-        }
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function has($key)
-    {
-        try {
-            return $this->pool->hasItem($key);
-        } catch (SimpleCacheException $e) {
-            throw $e;
-        } catch (Psr6CacheException $e) {
-            throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
-        }
-    }
 }
diff --git a/src/Symfony/Component/Cache/Simple/RedisCache.php b/src/Symfony/Component/Cache/Simple/RedisCache.php
index df2a96e86b580..2933bf15b3b52 100644
--- a/src/Symfony/Component/Cache/Simple/RedisCache.php
+++ b/src/Symfony/Component/Cache/Simple/RedisCache.php
@@ -11,9 +11,16 @@
 
 namespace Symfony\Component\Cache\Simple;
 
+use Symfony\Component\Cache\Adapter\RedisAdapter;
 use Symfony\Component\Cache\Marshaller\MarshallerInterface;
 use Symfony\Component\Cache\Traits\RedisTrait;
+use Symfony\Contracts\Cache\CacheInterface;
 
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', RedisCache::class, RedisAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
+
+/**
+ * @deprecated since Symfony 4.3, use RedisAdapter and type-hint for CacheInterface instead.
+ */
 class RedisCache extends AbstractCache
 {
     use RedisTrait;
diff --git a/src/Symfony/Component/Cache/Simple/TraceableCache.php b/src/Symfony/Component/Cache/Simple/TraceableCache.php
index 2db335ac968a1..ad9bfcf09ca60 100644
--- a/src/Symfony/Component/Cache/Simple/TraceableCache.php
+++ b/src/Symfony/Component/Cache/Simple/TraceableCache.php
@@ -11,23 +11,24 @@
 
 namespace Symfony\Component\Cache\Simple;
 
-use Psr\SimpleCache\CacheInterface;
+use Psr\SimpleCache\CacheInterface as Psr16CacheInterface;
 use Symfony\Component\Cache\PruneableInterface;
 use Symfony\Component\Cache\ResettableInterface;
+use Symfony\Contracts\Cache\CacheInterface;
 use Symfony\Contracts\Service\ResetInterface;
 
+@trigger_error(sprintf('The "%s" class is deprecated since Symfony 4.3, use "%s" and type-hint for "%s" instead.', TraceableCache::class, TraceableAdapter::class, CacheInterface::class), E_USER_DEPRECATED);
+
 /**
- * An adapter that collects data about all cache calls.
- *
- * @author Nicolas Grekas <p@tchwork.com>
+ * @deprecated since Symfony 4.3, use TraceableAdapter and type-hint for CacheInterface instead.
  */
-class TraceableCache implements CacheInterface, PruneableInterface, ResettableInterface
+class TraceableCache implements Psr16CacheInterface, PruneableInterface, ResettableInterface
 {
     private $pool;
     private $miss;
     private $calls = [];
 
-    public function __construct(CacheInterface $pool)
+    public function __construct(Psr16CacheInterface $pool)
     {
         $this->pool = $pool;
         $this->miss = new \stdClass();
diff --git a/src/Symfony/Component/Cache/Tests/Adapter/Psr16AdapterTest.php b/src/Symfony/Component/Cache/Tests/Adapter/Psr16AdapterTest.php
new file mode 100644
index 0000000000000..19907ddf78733
--- /dev/null
+++ b/src/Symfony/Component/Cache/Tests/Adapter/Psr16AdapterTest.php
@@ -0,0 +1,31 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Tests\Adapter;
+
+use Symfony\Component\Cache\Adapter\FilesystemAdapter;
+use Symfony\Component\Cache\Adapter\Psr16Adapter;
+use Symfony\Component\Cache\Psr16Cache;
+
+/**
+ * @group time-sensitive
+ */
+class Psr16AdapterTest extends AdapterTestCase
+{
+    protected $skippedTests = [
+        'testPrune' => 'Psr16adapter just proxies',
+    ];
+
+    public function createCachePool($defaultLifetime = 0)
+    {
+        return new Psr16Adapter(new Psr16Cache(new FilesystemAdapter()), '', $defaultLifetime);
+    }
+}
diff --git a/src/Symfony/Component/Cache/Tests/Adapter/SimpleCacheAdapterTest.php b/src/Symfony/Component/Cache/Tests/Adapter/SimpleCacheAdapterTest.php
index 3028af47c6f2a..b11f72d5a395b 100644
--- a/src/Symfony/Component/Cache/Tests/Adapter/SimpleCacheAdapterTest.php
+++ b/src/Symfony/Component/Cache/Tests/Adapter/SimpleCacheAdapterTest.php
@@ -11,12 +11,12 @@
 
 namespace Symfony\Component\Cache\Tests\Adapter;
 
-use Symfony\Component\Cache\Adapter\FilesystemAdapter;
 use Symfony\Component\Cache\Adapter\SimpleCacheAdapter;
-use Symfony\Component\Cache\Simple\Psr6Cache;
+use Symfony\Component\Cache\Simple\FilesystemCache;
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class SimpleCacheAdapterTest extends AdapterTestCase
 {
@@ -26,6 +26,6 @@ class SimpleCacheAdapterTest extends AdapterTestCase
 
     public function createCachePool($defaultLifetime = 0)
     {
-        return new SimpleCacheAdapter(new Psr6Cache(new FilesystemAdapter()), '', $defaultLifetime);
+        return new SimpleCacheAdapter(new FilesystemCache(), '', $defaultLifetime);
     }
 }
diff --git a/src/Symfony/Component/Cache/Tests/Psr16CacheTest.php b/src/Symfony/Component/Cache/Tests/Psr16CacheTest.php
new file mode 100644
index 0000000000000..8fb10f237286b
--- /dev/null
+++ b/src/Symfony/Component/Cache/Tests/Psr16CacheTest.php
@@ -0,0 +1,173 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Tests;
+
+use Cache\IntegrationTests\SimpleCacheTest;
+use Symfony\Component\Cache\Adapter\FilesystemAdapter;
+use Symfony\Component\Cache\PruneableInterface;
+use Symfony\Component\Cache\Psr16Cache;
+
+/**
+ * @group time-sensitive
+ */
+class Psr16CacheTest extends SimpleCacheTest
+{
+    protected function setUp()
+    {
+        parent::setUp();
+
+        if (array_key_exists('testPrune', $this->skippedTests)) {
+            return;
+        }
+
+        $pool = $this->createSimpleCache();
+        if ($pool instanceof Psr16Cache) {
+            $pool = ((array) $pool)[sprintf("\0%s\0pool", Psr16Cache::class)];
+        }
+
+        if (!$pool instanceof PruneableInterface) {
+            $this->skippedTests['testPrune'] = 'Not a pruneable cache pool.';
+        }
+    }
+
+    public function createSimpleCache($defaultLifetime = 0)
+    {
+        return new Psr16Cache(new FilesystemAdapter('', $defaultLifetime));
+    }
+
+    public static function validKeys()
+    {
+        return array_merge(parent::validKeys(), [["a\0b"]]);
+    }
+
+    public function testDefaultLifeTime()
+    {
+        if (isset($this->skippedTests[__FUNCTION__])) {
+            $this->markTestSkipped($this->skippedTests[__FUNCTION__]);
+        }
+
+        $cache = $this->createSimpleCache(2);
+        $cache->clear();
+
+        $cache->set('key.dlt', 'value');
+        sleep(1);
+
+        $this->assertSame('value', $cache->get('key.dlt'));
+
+        sleep(2);
+        $this->assertNull($cache->get('key.dlt'));
+
+        $cache->clear();
+    }
+
+    public function testNotUnserializable()
+    {
+        if (isset($this->skippedTests[__FUNCTION__])) {
+            $this->markTestSkipped($this->skippedTests[__FUNCTION__]);
+        }
+
+        $cache = $this->createSimpleCache();
+        $cache->clear();
+
+        $cache->set('foo', new NotUnserializable());
+
+        $this->assertNull($cache->get('foo'));
+
+        $cache->setMultiple(['foo' => new NotUnserializable()]);
+
+        foreach ($cache->getMultiple(['foo']) as $value) {
+        }
+        $this->assertNull($value);
+
+        $cache->clear();
+    }
+
+    public function testPrune()
+    {
+        if (isset($this->skippedTests[__FUNCTION__])) {
+            $this->markTestSkipped($this->skippedTests[__FUNCTION__]);
+        }
+
+        /** @var PruneableInterface|CacheInterface $cache */
+        $cache = $this->createSimpleCache();
+        $cache->clear();
+
+        $cache->set('foo', 'foo-val', new \DateInterval('PT05S'));
+        $cache->set('bar', 'bar-val', new \DateInterval('PT10S'));
+        $cache->set('baz', 'baz-val', new \DateInterval('PT15S'));
+        $cache->set('qux', 'qux-val', new \DateInterval('PT20S'));
+
+        sleep(30);
+        $cache->prune();
+        $this->assertTrue($this->isPruned($cache, 'foo'));
+        $this->assertTrue($this->isPruned($cache, 'bar'));
+        $this->assertTrue($this->isPruned($cache, 'baz'));
+        $this->assertTrue($this->isPruned($cache, 'qux'));
+
+        $cache->set('foo', 'foo-val');
+        $cache->set('bar', 'bar-val', new \DateInterval('PT20S'));
+        $cache->set('baz', 'baz-val', new \DateInterval('PT40S'));
+        $cache->set('qux', 'qux-val', new \DateInterval('PT80S'));
+
+        $cache->prune();
+        $this->assertFalse($this->isPruned($cache, 'foo'));
+        $this->assertFalse($this->isPruned($cache, 'bar'));
+        $this->assertFalse($this->isPruned($cache, 'baz'));
+        $this->assertFalse($this->isPruned($cache, 'qux'));
+
+        sleep(30);
+        $cache->prune();
+        $this->assertFalse($this->isPruned($cache, 'foo'));
+        $this->assertTrue($this->isPruned($cache, 'bar'));
+        $this->assertFalse($this->isPruned($cache, 'baz'));
+        $this->assertFalse($this->isPruned($cache, 'qux'));
+
+        sleep(30);
+        $cache->prune();
+        $this->assertFalse($this->isPruned($cache, 'foo'));
+        $this->assertTrue($this->isPruned($cache, 'baz'));
+        $this->assertFalse($this->isPruned($cache, 'qux'));
+
+        sleep(30);
+        $cache->prune();
+        $this->assertFalse($this->isPruned($cache, 'foo'));
+        $this->assertTrue($this->isPruned($cache, 'qux'));
+
+        $cache->clear();
+    }
+
+    protected function isPruned($cache, $name)
+    {
+        if (Psr16Cache::class !== \get_class($cache)) {
+            $this->fail('Test classes for pruneable caches must implement `isPruned($cache, $name)` method.');
+        }
+
+        $pool = ((array) $cache)[sprintf("\0%s\0pool", Psr16Cache::class)];
+        $getFileMethod = (new \ReflectionObject($pool))->getMethod('getFile');
+        $getFileMethod->setAccessible(true);
+
+        return !file_exists($getFileMethod->invoke($pool, $name));
+    }
+}
+
+class NotUnserializable implements \Serializable
+{
+    public function serialize()
+    {
+        return serialize(123);
+    }
+
+    public function unserialize($ser)
+    {
+        throw new \Exception(__CLASS__);
+    }
+}
diff --git a/src/Symfony/Component/Cache/Tests/Simple/AbstractRedisCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/AbstractRedisCacheTest.php
index dd5e1509c1bcc..a9f5d98b92a44 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/AbstractRedisCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/AbstractRedisCacheTest.php
@@ -13,6 +13,9 @@
 
 use Symfony\Component\Cache\Simple\RedisCache;
 
+/**
+ * @group legacy
+ */
 abstract class AbstractRedisCacheTest extends CacheTestCase
 {
     protected $skippedTests = [
diff --git a/src/Symfony/Component/Cache/Tests/Simple/ApcuCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/ApcuCacheTest.php
index f37b95a093fad..b3220946038cd 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/ApcuCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/ApcuCacheTest.php
@@ -13,6 +13,9 @@
 
 use Symfony\Component\Cache\Simple\ApcuCache;
 
+/**
+ * @group legacy
+ */
 class ApcuCacheTest extends CacheTestCase
 {
     protected $skippedTests = [
diff --git a/src/Symfony/Component/Cache/Tests/Simple/ArrayCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/ArrayCacheTest.php
index 26c3e14d0965c..587304a5db1c4 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/ArrayCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/ArrayCacheTest.php
@@ -15,6 +15,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class ArrayCacheTest extends CacheTestCase
 {
diff --git a/src/Symfony/Component/Cache/Tests/Simple/ChainCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/ChainCacheTest.php
index e6f7c7cc63229..806bb7633b222 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/ChainCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/ChainCacheTest.php
@@ -19,6 +19,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class ChainCacheTest extends CacheTestCase
 {
diff --git a/src/Symfony/Component/Cache/Tests/Simple/DoctrineCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/DoctrineCacheTest.php
index af4331d69b5a0..5d78c00cac841 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/DoctrineCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/DoctrineCacheTest.php
@@ -16,6 +16,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class DoctrineCacheTest extends CacheTestCase
 {
diff --git a/src/Symfony/Component/Cache/Tests/Simple/FilesystemCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/FilesystemCacheTest.php
index 620305a58a44e..9f423ba641c93 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/FilesystemCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/FilesystemCacheTest.php
@@ -16,6 +16,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class FilesystemCacheTest extends CacheTestCase
 {
diff --git a/src/Symfony/Component/Cache/Tests/Simple/MemcachedCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/MemcachedCacheTest.php
index f83f0a2e34527..692259296f21d 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/MemcachedCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/MemcachedCacheTest.php
@@ -14,6 +14,9 @@
 use Symfony\Component\Cache\Adapter\AbstractAdapter;
 use Symfony\Component\Cache\Simple\MemcachedCache;
 
+/**
+ * @group legacy
+ */
 class MemcachedCacheTest extends CacheTestCase
 {
     protected $skippedTests = [
diff --git a/src/Symfony/Component/Cache/Tests/Simple/MemcachedCacheTextModeTest.php b/src/Symfony/Component/Cache/Tests/Simple/MemcachedCacheTextModeTest.php
index 13865a6098e17..d68131a1db7bd 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/MemcachedCacheTextModeTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/MemcachedCacheTextModeTest.php
@@ -14,6 +14,9 @@
 use Symfony\Component\Cache\Adapter\AbstractAdapter;
 use Symfony\Component\Cache\Simple\MemcachedCache;
 
+/**
+ * @group legacy
+ */
 class MemcachedCacheTextModeTest extends MemcachedCacheTest
 {
     public function createSimpleCache($defaultLifetime = 0)
diff --git a/src/Symfony/Component/Cache/Tests/Simple/NullCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/NullCacheTest.php
index 31f42c32b6a8c..cf0dde92b33f4 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/NullCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/NullCacheTest.php
@@ -16,6 +16,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class NullCacheTest extends TestCase
 {
diff --git a/src/Symfony/Component/Cache/Tests/Simple/PdoCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/PdoCacheTest.php
index 665db09f672a0..fbdf03be7ee50 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/PdoCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/PdoCacheTest.php
@@ -16,6 +16,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class PdoCacheTest extends CacheTestCase
 {
diff --git a/src/Symfony/Component/Cache/Tests/Simple/PdoDbalCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/PdoDbalCacheTest.php
index ce1a9ae4f8c6e..af5c42340b4fc 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/PdoDbalCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/PdoDbalCacheTest.php
@@ -17,6 +17,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class PdoDbalCacheTest extends CacheTestCase
 {
diff --git a/src/Symfony/Component/Cache/Tests/Simple/PhpArrayCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/PhpArrayCacheTest.php
index ba4bde3139517..5272604dc32cf 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/PhpArrayCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/PhpArrayCacheTest.php
@@ -17,6 +17,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class PhpArrayCacheTest extends CacheTestCase
 {
@@ -127,35 +128,3 @@ public function testStoredFile()
         $this->assertSame($expected, $values, 'Warm up should create a PHP file that OPCache can load in memory');
     }
 }
-
-class PhpArrayCacheWrapper extends PhpArrayCache
-{
-    protected $data = [];
-
-    public function set($key, $value, $ttl = null)
-    {
-        (\Closure::bind(function () use ($key, $value) {
-            $this->data[$key] = $value;
-            $this->warmUp($this->data);
-            list($this->keys, $this->values) = eval(substr(file_get_contents($this->file), 6));
-        }, $this, PhpArrayCache::class))();
-
-        return true;
-    }
-
-    public function setMultiple($values, $ttl = null)
-    {
-        if (!\is_array($values) && !$values instanceof \Traversable) {
-            return parent::setMultiple($values, $ttl);
-        }
-        (\Closure::bind(function () use ($values) {
-            foreach ($values as $key => $value) {
-                $this->data[$key] = $value;
-            }
-            $this->warmUp($this->data);
-            list($this->keys, $this->values) = eval(substr(file_get_contents($this->file), 6));
-        }, $this, PhpArrayCache::class))();
-
-        return true;
-    }
-}
diff --git a/src/Symfony/Component/Cache/Tests/Simple/PhpArrayCacheWithFallbackTest.php b/src/Symfony/Component/Cache/Tests/Simple/PhpArrayCacheWithFallbackTest.php
index abee5e7872164..90aa7bb6ef835 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/PhpArrayCacheWithFallbackTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/PhpArrayCacheWithFallbackTest.php
@@ -17,6 +17,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class PhpArrayCacheWithFallbackTest extends CacheTestCase
 {
diff --git a/src/Symfony/Component/Cache/Tests/Simple/PhpArrayCacheWrapper.php b/src/Symfony/Component/Cache/Tests/Simple/PhpArrayCacheWrapper.php
new file mode 100644
index 0000000000000..1e102fe1ff2e3
--- /dev/null
+++ b/src/Symfony/Component/Cache/Tests/Simple/PhpArrayCacheWrapper.php
@@ -0,0 +1,46 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Tests\Simple;
+
+use Symfony\Component\Cache\Simple\PhpArrayCache;
+
+class PhpArrayCacheWrapper extends PhpArrayCache
+{
+    protected $data = [];
+
+    public function set($key, $value, $ttl = null)
+    {
+        (\Closure::bind(function () use ($key, $value) {
+            $this->data[$key] = $value;
+            $this->warmUp($this->data);
+            list($this->keys, $this->values) = eval(substr(file_get_contents($this->file), 6));
+        }, $this, PhpArrayCache::class))();
+
+        return true;
+    }
+
+    public function setMultiple($values, $ttl = null)
+    {
+        if (!\is_array($values) && !$values instanceof \Traversable) {
+            return parent::setMultiple($values, $ttl);
+        }
+        (\Closure::bind(function () use ($values) {
+            foreach ($values as $key => $value) {
+                $this->data[$key] = $value;
+            }
+            $this->warmUp($this->data);
+            list($this->keys, $this->values) = eval(substr(file_get_contents($this->file), 6));
+        }, $this, PhpArrayCache::class))();
+
+        return true;
+    }
+}
diff --git a/src/Symfony/Component/Cache/Tests/Simple/PhpFilesCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/PhpFilesCacheTest.php
index 3a68dd39842e7..7e40df7de5fbd 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/PhpFilesCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/PhpFilesCacheTest.php
@@ -16,6 +16,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class PhpFilesCacheTest extends CacheTestCase
 {
diff --git a/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheTest.php
index 65d48a978c503..9fff36e402dee 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheTest.php
@@ -13,6 +13,9 @@
 
 use Symfony\Component\Cache\Simple\Psr6Cache;
 
+/**
+ * @group legacy
+ */
 abstract class Psr6CacheTest extends CacheTestCase
 {
     protected $skippedTests = [
diff --git a/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheWithAdapterTest.php b/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheWithAdapterTest.php
index 46da9354d6db5..e5c7a6a4c7e9a 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheWithAdapterTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheWithAdapterTest.php
@@ -15,6 +15,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class Psr6CacheWithAdapterTest extends Psr6CacheTest
 {
diff --git a/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheWithoutAdapterTest.php b/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheWithoutAdapterTest.php
index a8c4164dcbb1d..f987d405396c6 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheWithoutAdapterTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/Psr6CacheWithoutAdapterTest.php
@@ -15,6 +15,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class Psr6CacheWithoutAdapterTest extends Psr6CacheTest
 {
diff --git a/src/Symfony/Component/Cache/Tests/Simple/RedisArrayCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/RedisArrayCacheTest.php
index bda39d990bcb3..b52f5f9acde9f 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/RedisArrayCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/RedisArrayCacheTest.php
@@ -11,6 +11,9 @@
 
 namespace Symfony\Component\Cache\Tests\Simple;
 
+/**
+ * @group legacy
+ */
 class RedisArrayCacheTest extends AbstractRedisCacheTest
 {
     public static function setupBeforeClass()
diff --git a/src/Symfony/Component/Cache/Tests/Simple/RedisCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/RedisCacheTest.php
index 407d916c7317c..ddb674b285dda 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/RedisCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/RedisCacheTest.php
@@ -13,6 +13,9 @@
 
 use Symfony\Component\Cache\Simple\RedisCache;
 
+/**
+ * @group legacy
+ */
 class RedisCacheTest extends AbstractRedisCacheTest
 {
     public static function setupBeforeClass()
diff --git a/src/Symfony/Component/Cache/Tests/Simple/RedisClusterCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/RedisClusterCacheTest.php
index 99d4e518fb409..33c7acae0b822 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/RedisClusterCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/RedisClusterCacheTest.php
@@ -11,6 +11,9 @@
 
 namespace Symfony\Component\Cache\Tests\Simple;
 
+/**
+ * @group legacy
+ */
 class RedisClusterCacheTest extends AbstractRedisCacheTest
 {
     public static function setupBeforeClass()
diff --git a/src/Symfony/Component/Cache/Tests/Simple/TraceableCacheTest.php b/src/Symfony/Component/Cache/Tests/Simple/TraceableCacheTest.php
index e684caf36e8f9..c2e8a477b4771 100644
--- a/src/Symfony/Component/Cache/Tests/Simple/TraceableCacheTest.php
+++ b/src/Symfony/Component/Cache/Tests/Simple/TraceableCacheTest.php
@@ -16,6 +16,7 @@
 
 /**
  * @group time-sensitive
+ * @group legacy
  */
 class TraceableCacheTest extends CacheTestCase
 {
diff --git a/src/Symfony/Component/Cache/composer.json b/src/Symfony/Component/Cache/composer.json
index c11af6d8f19af..f9b5e18381795 100644
--- a/src/Symfony/Component/Cache/composer.json
+++ b/src/Symfony/Component/Cache/composer.json
@@ -24,7 +24,6 @@
         "php": "^7.1.3",
         "psr/cache": "~1.0",
         "psr/log": "~1.0",
-        "psr/simple-cache": "^1.0",
         "symfony/contracts": "^1.0",
         "symfony/var-exporter": "^4.2"
     },
@@ -33,6 +32,7 @@
         "doctrine/cache": "~1.6",
         "doctrine/dbal": "~2.5",
         "predis/predis": "~1.1",
+        "psr/simple-cache": "^1.0",
         "symfony/config": "~4.2",
         "symfony/dependency-injection": "~3.4|~4.1",
         "symfony/var-dumper": "^4.1.1"

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