diff --git a/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php b/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php
index 7523ab85f1..51b2bbd6c5 100644
--- a/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php
@@ -27,6 +27,11 @@ use Symfony\Contracts\Cache\CacheInterface;
  */
 abstract class AbstractAdapter implements AdapterInterface, CacheInterface, LoggerAwareInterface, ResettableInterface
 {
+    /**
+     * @internal
+     */
+    protected const NS_SEPARATOR = ':';
+
     use AbstractTrait;
     use ContractsTrait;
 
@@ -38,7 +43,7 @@ abstract class AbstractAdapter implements AdapterInterface, CacheInterface, Logg
 
     protected function __construct(string $namespace = '', int $defaultLifetime = 0)
     {
-        $this->namespace = '' === $namespace ? '' : CacheItem::validateKey($namespace).static::getNsSeparator();
+        $this->namespace = '' === $namespace ? '' : CacheItem::validateKey($namespace).static::NS_SEPARATOR;
         if (null !== $this->maxIdLength && \strlen($namespace) > $this->maxIdLength - 24) {
             throw new InvalidArgumentException(sprintf('Namespace must be %d chars max, %d given ("%s")', $this->maxIdLength - 24, \strlen($namespace), $namespace));
         }
diff --git a/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php b/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php
index 8dbf31ff20..cc48e531c6 100644
--- a/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/SimpleCacheAdapter.php
@@ -20,6 +20,11 @@ use Symfony\Component\Cache\Traits\ProxyTrait;
  */
 class SimpleCacheAdapter extends AbstractAdapter implements PruneableInterface
 {
+    /**
+     * @internal
+     */
+    protected const NS_SEPARATOR = '_';
+
     use ProxyTrait;
 
     private $miss;
@@ -75,12 +80,4 @@ class SimpleCacheAdapter extends AbstractAdapter implements PruneableInterface
     {
         return $this->pool->setMultiple($values, 0 === $lifetime ? null : $lifetime);
     }
-
-    /**
-     * @return string the namespace separator for cache keys
-     */
-    protected static function getNsSeparator()
-    {
-        return '_';
-    }
 }
diff --git a/src/Symfony/Component/Cache/Simple/AbstractCache.php b/src/Symfony/Component/Cache/Simple/AbstractCache.php
index 7a2a3cb36e..cb9e44c859 100644
--- a/src/Symfony/Component/Cache/Simple/AbstractCache.php
+++ b/src/Symfony/Component/Cache/Simple/AbstractCache.php
@@ -23,6 +23,11 @@ use Symfony\Component\Cache\Traits\AbstractTrait;
  */
 abstract class AbstractCache implements CacheInterface, LoggerAwareInterface, ResettableInterface
 {
+    /**
+     * @internal
+     */
+    protected const NS_SEPARATOR = ':';
+
     use AbstractTrait {
         deleteItems as private;
         AbstractTrait::deleteItem as delete;
diff --git a/src/Symfony/Component/Cache/Traits/AbstractTrait.php b/src/Symfony/Component/Cache/Traits/AbstractTrait.php
index 4fe5b9bf1a..f92e541d35 100644
--- a/src/Symfony/Component/Cache/Traits/AbstractTrait.php
+++ b/src/Symfony/Component/Cache/Traits/AbstractTrait.php
@@ -107,9 +107,9 @@ trait AbstractTrait
     {
         $this->deferred = [];
         if ($cleared = $this->versioningIsEnabled) {
-            $namespaceVersion = substr_replace(base64_encode(pack('V', mt_rand())), static::getNsSeparator(), 5);
+            $namespaceVersion = substr_replace(base64_encode(pack('V', mt_rand())), static::NS_SEPARATOR, 5);
             try {
-                $cleared = $this->doSave([static::getNsSeparator().$this->namespace => $namespaceVersion], 0);
+                $cleared = $this->doSave([static::NS_SEPARATOR.$this->namespace => $namespaceVersion], 0);
             } catch (\Exception $e) {
                 $cleared = false;
             }
@@ -242,14 +242,14 @@ trait AbstractTrait
     {
         if ($this->versioningIsEnabled && '' === $this->namespaceVersion) {
             $this->ids = [];
-            $this->namespaceVersion = '1'.static::getNsSeparator();
+            $this->namespaceVersion = '1'.static::NS_SEPARATOR;
             try {
-                foreach ($this->doFetch([static::getNsSeparator().$this->namespace]) as $v) {
+                foreach ($this->doFetch([static::NS_SEPARATOR.$this->namespace]) as $v) {
                     $this->namespaceVersion = $v;
                 }
-                if ('1'.static::getNsSeparator() === $this->namespaceVersion) {
-                    $this->namespaceVersion = substr_replace(base64_encode(pack('V', time())), static::getNsSeparator(), 5);
-                    $this->doSave([static::getNsSeparator().$this->namespace => $this->namespaceVersion], 0);
+                if ('1'.static::NS_SEPARATOR === $this->namespaceVersion) {
+                    $this->namespaceVersion = substr_replace(base64_encode(pack('V', time())), static::NS_SEPARATOR, 5);
+                    $this->doSave([static::NS_SEPARATOR.$this->namespace => $this->namespaceVersion], 0);
                 }
             } catch (\Exception $e) {
             }
@@ -266,7 +266,7 @@ trait AbstractTrait
         }
         if (\strlen($id = $this->namespace.$this->namespaceVersion.$key) > $this->maxIdLength) {
             // Use MD5 to favor speed over security, which is not an issue here
-            $this->ids[$key] = $id = substr_replace(base64_encode(hash('md5', $key, true)), static::getNsSeparator(), -(\strlen($this->namespaceVersion) + 2));
+            $this->ids[$key] = $id = substr_replace(base64_encode(hash('md5', $key, true)), static::NS_SEPARATOR, -(\strlen($this->namespaceVersion) + 2));
             $id = $this->namespace.$this->namespaceVersion.$id;
         }
 
@@ -280,12 +280,4 @@ trait AbstractTrait
     {
         throw new \DomainException('Class not found: '.$class);
     }
-
-    /**
-     * @return string the namespace separator for cache keys
-     */
-    protected static function getNsSeparator()
-    {
-        return ':';
-    }
 }