diff --git a/src/Text/Pandoc/Pretty.hs b/src/Text/Pandoc/Pretty.hs
index 033511832..5331587ce 100644
--- a/src/Text/Pandoc/Pretty.hs
+++ b/src/Text/Pandoc/Pretty.hs
@@ -81,8 +81,7 @@ import Data.String
 import Control.Monad.State
 import Data.Char (isSpace)
 
-data Monoid a =>
-     RenderState a = RenderState{
+data RenderState a = RenderState{
          output       :: [a]        -- ^ In reverse order
        , prefix       :: String
        , usePrefix    :: Bool