diff --git a/src/Symfony/Component/HttpFoundation/File/MimeType/FileinfoMimeTypeGuesser.php b/src/Symfony/Component/HttpFoundation/File/MimeType/FileinfoMimeTypeGuesser.php
index 09a0d7ed19..a6950df2cd 100644
--- a/src/Symfony/Component/HttpFoundation/File/MimeType/FileinfoMimeTypeGuesser.php
+++ b/src/Symfony/Component/HttpFoundation/File/MimeType/FileinfoMimeTypeGuesser.php
@@ -15,12 +15,26 @@ use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
 use Symfony\Component\HttpFoundation\File\Exception\AccessDeniedException;
 
 /**
- * Guesses the mime type using the PECL extension FileInfo
+ * Guesses the mime type using the PECL extension FileInfo.
  *
  * @author Bernhard Schussek <bschussek@gmail.com>
  */
 class FileinfoMimeTypeGuesser implements MimeTypeGuesserInterface
 {
+    private $magicFile;
+
+    /**
+     * Constructor.
+     *
+     * @param string $magicFile A magic file to use with the finfo instance
+     *
+     * @link http://www.php.net/manual/en/function.finfo-open.php
+     */
+    public function __construct($magicFile = null)
+    {
+        $this->magicFile = $magicFile;
+    }
+
     /**
      * Returns whether this guesser is supported on the current OS/PHP setup
      *
@@ -48,7 +62,7 @@ class FileinfoMimeTypeGuesser implements MimeTypeGuesserInterface
             return null;
         }
 
-        if (!$finfo = new \finfo(FILEINFO_MIME_TYPE)) {
+        if (!$finfo = new \finfo(FILEINFO_MIME_TYPE, $this->magicFile)) {
             return null;
         }
 
diff --git a/src/Symfony/Component/HttpFoundation/File/MimeType/MimeTypeGuesser.php b/src/Symfony/Component/HttpFoundation/File/MimeType/MimeTypeGuesser.php
index 88720c00b5..f6bf2cd39d 100644
--- a/src/Symfony/Component/HttpFoundation/File/MimeType/MimeTypeGuesser.php
+++ b/src/Symfony/Component/HttpFoundation/File/MimeType/MimeTypeGuesser.php
@@ -23,15 +23,17 @@ use Symfony\Component\HttpFoundation\File\Exception\AccessDeniedException;
  * You can register custom guessers by calling the register() method on the
  * singleton instance. Custom guessers are always called before any default ones.
  *
+ *     $guesser = MimeTypeGuesser::getInstance();
+ *     $guesser->register(new MyCustomMimeTypeGuesser());
+ *
  * If you want to change the order of the default guessers, just re-register your
- * preferred one as a custom one.
+ * preferred one as a custom one. The last registered guesser is preferred over
+ * previously registered ones.
  *
- * <code>
- * $guesser = MimeTypeGuesser::getInstance();
- * $guesser->register(new MyCustomMimeTypeGuesser());
- * </code>
+ * Re-registering a built-in guesser also allows you to configure it:
  *
- * The last registered guesser is preferred over previously registered ones.
+ *     $guesser = MimeTypeGuesser::getInstance();
+ *     $guesser->register(new FileinfoMimeTypeGuesser('/path/to/magic/file'));
  *
  * @author Bernhard Schussek <bschussek@gmail.com>
  */