diff --git a/RabbitMq/Fallback.php b/RabbitMq/Fallback.php
index e946ccaf..2f90f605 100644
--- a/RabbitMq/Fallback.php
+++ b/RabbitMq/Fallback.php
@@ -2,10 +2,24 @@
 
 namespace OldSound\RabbitMqBundle\RabbitMq;
 
+/**
+ * Fallback producer for sandbox mode.
+ */
 class Fallback implements ProducerInterface
 {
+    /**
+     * {@inheritDoc}
+     */
     public function publish($msgBody, $routingKey = '', $additionalProperties = array())
     {
         return false;
     }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function setContentType($contentType)
+    {
+    }
 }
+
diff --git a/RabbitMq/ProducerInterface.php b/RabbitMq/ProducerInterface.php
index b4e166c1..9580cdd2 100644
--- a/RabbitMq/ProducerInterface.php
+++ b/RabbitMq/ProducerInterface.php
@@ -12,4 +12,12 @@ interface ProducerInterface
      * @param array $additionalProperties
      */
     public function publish($msgBody, $routingKey = '', $additionalProperties = array());
+
+    /**
+     * Set message content type
+     *
+     * @param string $contentType
+     */
+    public function setContentType($contentType);
 }
+