diff --git a/Shellish.hs b/Shellish.hs
index 1e3c192..0ac20c2 100644
--- a/Shellish.hs
+++ b/Shellish.hs
@@ -1,3 +1,3 @@
 {-# LANGUAGE ScopedTypeVariables, DeriveDataTypeable, OverloadedStrings,
-             MultiParamTypeClasses, FlexibleInstances #-}
+             MultiParamTypeClasses, FlexibleInstances, FlexibleContexts #-}
 
