diff --git a/src/Symfony/Component/Config/ConfigCache.php b/src/Symfony/Component/Config/ConfigCache.php
index cbb198427260..07d47917c76d 100644
--- a/src/Symfony/Component/Config/ConfigCache.php
+++ b/src/Symfony/Component/Config/ConfigCache.php
@@ -15,17 +15,15 @@
 use Symfony\Component\Filesystem\Filesystem;
 
 /**
- * ConfigCache manages PHP cache files.
- *
- * When debug is enabled, it knows when to flush the cache
- * thanks to an array of ResourceInterface instances.
+ * ConfigCache is a backwards-compatible way of using the
+ * cache implementation classes.
  *
  * @author Fabien Potencier <fabien@symfony.com>
+ * @author Matthias Pigulla <mp@webfactory.de>
  */
 class ConfigCache
 {
-    private $debug;
-    private $file;
+    private $cacheImplementation;
 
     /**
      * Constructor.
@@ -35,8 +33,11 @@ class ConfigCache
      */
     public function __construct($file, $debug)
     {
-        $this->file = $file;
-        $this->debug = (Boolean) $debug;
+        if ($debug) {
+            $this->cacheImplementation = new ResourceValidatingCache($file);
+        } else {
+            $this->cacheImplementation = new NonvalidatingCache($file);
+        }
     }
 
     /**
@@ -46,7 +47,7 @@ public function __construct($file, $debug)
      */
     public function __toString()
     {
-        return $this->file;
+        return $this->cacheImplementation->__toString();
     }
 
     /**
@@ -59,28 +60,7 @@ public function __toString()
      */
     public function isFresh()
     {
-        if (!is_file($this->file)) {
-            return false;
-        }
-
-        if (!$this->debug) {
-            return true;
-        }
-
-        $metadata = $this->getMetaFile();
-        if (!is_file($metadata)) {
-            return false;
-        }
-
-        $time = filemtime($this->file);
-        $meta = unserialize(file_get_contents($metadata));
-        foreach ($meta as $resource) {
-            if (!$resource->isFresh($time)) {
-                return false;
-            }
-        }
-
-        return true;
+        return $this->cacheImplementation->isFresh();
     }
 
     /**
@@ -89,27 +69,10 @@ public function isFresh()
      * @param string              $content  The content to write in the cache
      * @param ResourceInterface[] $metadata An array of ResourceInterface instances
      *
-     * @throws \RuntimeException When cache file can't be wrote
+     * @throws \RuntimeException When the cache file cannot be written.
      */
     public function write($content, array $metadata = null)
     {
-        $mode = 0666 & ~umask();
-        $filesystem = new Filesystem();
-        $filesystem->dumpFile($this->file, $content, $mode);
-
-        if (null !== $metadata && true === $this->debug) {
-            $filesystem->dumpFile($this->getMetaFile(), serialize($metadata), $mode);
-        }
+        $this->cacheImplementation->write($content, $metadata);
     }
-
-    /**
-     * Gets the meta file path.
-     *
-     * @return string The meta file path
-     */
-    private function getMetaFile()
-    {
-        return $this->file.'.meta';
-    }
-
 }
diff --git a/src/Symfony/Component/Config/NonvalidatingCache.php b/src/Symfony/Component/Config/NonvalidatingCache.php
new file mode 100644
index 000000000000..342d73061ac7
--- /dev/null
+++ b/src/Symfony/Component/Config/NonvalidatingCache.php
@@ -0,0 +1,69 @@
+<?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\Config;
+
+use Symfony\Component\Config\Resource\ResourceInterface;
+use Symfony\Component\Filesystem\Filesystem;
+
+/**
+ * A cache that never expires once it has been written.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ * @author Matthias Pigulla <mp@webfactory.de>
+ */
+class NonvalidatingCache
+{
+    protected $file;
+
+    /**
+     * Constructor.
+     *
+     * @param string  $file  The absolute cache path
+     */
+    public function __construct($file)
+    {
+        $this->file = $file;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function __toString()
+    {
+        return $this->file;
+    }
+
+    /**
+     * By design, this method always returns true once the cache
+     * has been initialized.
+     *
+     * {@inheritdoc}
+     */
+    public function isFresh()
+    {
+        if (!is_file($this->file)) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * This implementation ignores the metadata.
+     * {@inheritdoc}
+     */
+    public function write($content, array $metadata = null)
+    {
+        $filesystem = new Filesystem();
+        $filesystem->dumpFile($this->file, $content, 0666 & ~umask());
+    }
+}
diff --git a/src/Symfony/Component/Config/ResourceValidatingCache.php b/src/Symfony/Component/Config/ResourceValidatingCache.php
new file mode 100644
index 000000000000..2539ce093874
--- /dev/null
+++ b/src/Symfony/Component/Config/ResourceValidatingCache.php
@@ -0,0 +1,86 @@
+<?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\Config;
+
+use Symfony\Component\Config\Resource\ResourceInterface;
+use Symfony\Component\Filesystem\Filesystem;
+
+/**
+ * ConfigCache manages PHP cache files.
+ *
+ * When debug is enabled, it knows when to flush the cache
+ * thanks to an array of ResourceInterface instances.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class ResourceValidatingCache extends NonvalidatingCache
+{
+
+    /**
+     * Checks if the cache is still fresh.
+     *
+     * This method evaluates the resources/metadata passed to the
+     * write() method.
+     *
+     * @return Boolean true if the cache is fresh, false otherwise
+     */
+    public function isFresh()
+    {
+        if (!parent::isFresh()) {
+            return false;
+        }
+
+        $metadata = $this->getMetaFile();
+        if (!is_file($metadata)) {
+            return false;
+        }
+
+        $time = filemtime($this->file);
+        $meta = unserialize(file_get_contents($metadata));
+        foreach ($meta as $resource) {
+            if (!$resource->isFresh($time)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * Writes cache.
+     *
+     * @param string              $content  The content to write in the cache
+     * @param ResourceInterface[] $metadata An array of ResourceInterface instances
+     *
+     * @throws \RuntimeException When cache file can't be wrote
+     */
+    public function write($content, array $metadata = null)
+    {
+        if (null !== $metadata) {
+            $filesystem = new Filesystem();
+            $filesystem->dumpFile($this->getMetaFile(), serialize($metadata), 0666 & ~umask());
+        }
+
+        parent::write($content);
+    }
+
+    /**
+     * Gets the meta file path.
+     *
+     * @return string The meta file path
+     */
+    private function getMetaFile()
+    {
+        return $this->file.'.meta';
+    }
+
+}