diff --git a/servant-foreign/src/Servant/Foreign.hs b/servant-foreign/src/Servant/Foreign.hs
index c42ccdc3..555a9146 100644
--- a/servant-foreign/src/Servant/Foreign.hs
+++ b/servant-foreign/src/Servant/Foreign.hs
@@ -4,6 +4,7 @@
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE NullaryTypeClasses    #-}
 {-# LANGUAGE ScopedTypeVariables   #-}
 {-# LANGUAGE TemplateHaskell       #-}
 {-# LANGUAGE TypeFamilies          #-}