diff --git a/bench/countDown.hs b/bench/countDown.hs
index 563483b..756eaac 100644
--- a/bench/countDown.hs
+++ b/bench/countDown.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE DataKinds, DeriveFunctor, FlexibleContexts, GADTs, TypeOperators #-}
 module Main (main) where
 
 import Control.Monad (replicateM_)