diff --git a/Encoder/DecoderInterface.php b/Encoder/DecoderInterface.php
index fb67f2969..f109753d6 100644
--- a/Encoder/DecoderInterface.php
+++ b/Encoder/DecoderInterface.php
@@ -13,7 +13,7 @@
  */
 
 /**
- * Defines the interface of encoders that are able to decode their own format
+ * Defines the interface of decoders
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
  */
@@ -22,9 +22,17 @@ interface DecoderInterface
     /**
      * Decodes a string into PHP data
      *
-     * @param string $data data to decode
-     * @param string $format format to decode from
+     * @param scalar $data data to decode
+     * @param string $format format name
      * @return mixed
      */
     function decode($data, $format);
+
+    /**
+     * Checks whether the serializer can decode from given format
+     *
+     * @param string $format format name
+     * @return Boolean
+     */
+    function supportsDecoding($format);
 }
diff --git a/Encoder/EncoderInterface.php b/Encoder/EncoderInterface.php
index 11ce30fb4..7d63e7cae 100644
--- a/Encoder/EncoderInterface.php
+++ b/Encoder/EncoderInterface.php
@@ -2,7 +2,6 @@
 
 namespace Symfony\Component\Serializer\Encoder;
 
-
 /*
  * This file is part of the Symfony framework.
  *
@@ -20,11 +19,19 @@
 interface EncoderInterface
 {
     /**
-     * Encodes data into a string
+     * Encodes data into the given format
      *
      * @param mixed $data data to encode
-     * @param string $format format to encode to
-     * @return string
+     * @param string $format format name
+     * @return scalar
      */
     function encode($data, $format);
+
+    /**
+     * Checks whether the serializer can encode to given format
+     *
+     * @param string $format format name
+     * @return Boolean
+     */
+    function supportsEncoding($format);
 }
diff --git a/Encoder/JsonEncoder.php b/Encoder/JsonEncoder.php
index 2e874eb61..620d749e7 100644
--- a/Encoder/JsonEncoder.php
+++ b/Encoder/JsonEncoder.php
@@ -34,4 +34,26 @@ public function decode($data, $format)
     {
         return json_decode($data, true);
     }
+
+    /**
+     * Checks whether the serializer can encode to given format
+     *
+     * @param string $format format name
+     * @return Boolean
+     */
+    public function supportsEncoding($format)
+    {
+        return 'json' === $format;
+    }
+
+    /**
+     * Checks whether the serializer can decode from given format
+     *
+     * @param string $format format name
+     * @return Boolean
+     */
+    public function supportsDecoding($format)
+    {
+        return 'json' === $format;
+    }
 }
diff --git a/Encoder/XmlEncoder.php b/Encoder/XmlEncoder.php
index 7fbde8e61..3a61c1a7b 100644
--- a/Encoder/XmlEncoder.php
+++ b/Encoder/XmlEncoder.php
@@ -71,6 +71,28 @@ public function decode($data, $format)
         return $this->parseXml($xml);
     }
 
+    /**
+      * Checks whether the serializer can encode to given format
+      *
+      * @param string $format format name
+      * @return Boolean
+      */
+     public function supportsEncoding($format)
+     {
+         return 'xml' === $format;
+     }
+
+     /**
+      * Checks whether the serializer can decode from given format
+      *
+      * @param string $format format name
+      * @return Boolean
+      */
+     public function supportsDecoding($format)
+     {
+         return 'xml' === $format;
+     }
+
     /**
      * Sets the root node name
      * @param string $name root node name
diff --git a/EncoderInterface.php b/EncoderInterface.php
deleted file mode 100644
index e4d79475c..000000000
--- a/EncoderInterface.php
+++ /dev/null
@@ -1,63 +0,0 @@
-<?php
-
-namespace Symfony\Component\Serializer;
-
-use Symfony\Component\Serializer\Encoder\EncoderInterface;
-
-/*
- * This file is part of the Symfony framework.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * This source file is subject to the MIT license that is bundled
- * with this source code in the file LICENSE.
- */
-
-/**
- * Defines the interface of the Encoder
- *
- * @author Jordi Boggiano <j.boggiano@seld.be>
- */
-interface EncoderInterface
-{
-    /**
-     * Encodes data into the given format
-     *
-     * @param mixed $data data to encode
-     * @param string $format format name
-     * @return array|scalar
-     */
-    function encode($data, $format);
-
-    /**
-     * Decodes a string from the given format back into PHP data
-     *
-     * @param string $data data to decode
-     * @param string $format format name
-     * @return mixed
-     */
-    function decode($data, $format);
-
-    /**
-     * Checks whether the serializer can encode to given format
-     *
-     * @param string $format format name
-     * @return Boolean
-     */
-    function supportsEncoding($format);
-
-    /**
-     * Checks whether the serializer can decode from given format
-     *
-     * @param string $format format name
-     * @return Boolean
-     */
-    function supportsDecoding($format);
-
-    /**
-     * Get the encoder for the given format
-     *
-     * @return EncoderInterface
-     */
-    function getEncoder($format);
-}
diff --git a/NormalizerInterface.php b/NormalizerInterface.php
index 706bed60a..d1fbe719f 100644
--- a/NormalizerInterface.php
+++ b/NormalizerInterface.php
@@ -2,8 +2,6 @@
 
 namespace Symfony\Component\Serializer;
 
-use Symfony\Component\Serializer\Encoder\EncoderInterface;
-
 /*
  * This file is part of the Symfony framework.
  *
@@ -14,7 +12,7 @@
  */
 
 /**
- * Defines the interface of the Normalizer
+ * Defines the interface of Normalizers
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
  */
diff --git a/Serializer.php b/Serializer.php
index 4c60942ba..8c861bd3a 100644
--- a/Serializer.php
+++ b/Serializer.php
@@ -32,7 +32,7 @@
  * @author Johannes M. Schmitt <schmittjoh@gmail.com>
  * @author Lukas Kahwe Smith <smith@pooteeweet.org>
  */
-class Serializer implements SerializerInterface, NormalizerInterface, EncoderInterface
+class Serializer implements SerializerInterface, NormalizerInterface, EncoderInterface, DecoderInterface
 {
     protected $normalizers = array();
     protected $encoders = array();