diff --git a/src/Monolog/Handler/FlowdockHandler.php b/src/Monolog/Handler/FlowdockHandler.php
index 70656c88..dd9a361c 100644
--- a/src/Monolog/Handler/FlowdockHandler.php
+++ b/src/Monolog/Handler/FlowdockHandler.php
@@ -13,6 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Logger;
 use Monolog\Formatter\FlowdockFormatter;
+use Monolog\Formatter\FormatterInterface;
 
 /**
  * Sends notifications through the Flowdock push API