diff --git a/servant/src/Servant/API/Status.hs b/servant/src/Servant/API/Status.hs
index 8f80938d..17a60766 100644
--- a/servant/src/Servant/API/Status.hs
+++ b/servant/src/Servant/API/Status.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE DataKinds #-}
+-- Flexible instances is necessary on GHC 8.4 and earlier
+{-# LANGUAGE FlexibleInstances #-}
 module Servant.API.Status where
 
 import Network.HTTP.Types.Status