diff --git a/src/Symfony/Component/VarDumper/Dumper/AbstractDumper.php b/src/Symfony/Component/VarDumper/Dumper/AbstractDumper.php
index 72c8258a62..30cd1a1b19 100644
--- a/src/Symfony/Component/VarDumper/Dumper/AbstractDumper.php
+++ b/src/Symfony/Component/VarDumper/Dumper/AbstractDumper.php
@@ -39,7 +39,7 @@ abstract class AbstractDumper implements DataDumperInterface, DumperInterface
 
     /**
      * @param callable|resource|string|null $output  A line dumper callable, an opened stream or an output path, defaults to static::$defaultOutput
-     * @param string                        $charset The default character encoding to use for non-UTF8 strings
+     * @param string|null                   $charset The default character encoding to use for non-UTF8 strings
      * @param int                           $flags   A bit field of static::DUMP_* constants to fine tune dumps representation
      */
     public function __construct($output = null, $charset = null, $flags = 0)