diff --git a/app/Main.hs b/app/Main.hs
index 1dcf39193..576bc6026 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -65,7 +65,7 @@ printDiff arguments diff sources = case format arguments of
       put chunks = do
         renderer <- byteStringMakerFromEnvironment
         B1.putStr $ mconcat $ chunksToByteStrings renderer chunks
-  Split -> put (output arguments) =<< split diff sources
+  Split -> put (output arguments) $ split diff sources
     where
       put Nothing rendered = TextIO.putStr rendered
       put (Just path) rendered = do
diff --git a/src/Split.hs b/src/Split.hs
index 7521c27da..4b0cf52e8 100644
--- a/src/Split.hs
+++ b/src/Split.hs
@@ -31,8 +31,8 @@ type ClassName = T.Text
 classifyMarkup :: Foldable f => f String -> Markup -> Markup
 classifyMarkup categories element = maybe element ((element !) . A.class_ . stringValue . ("category-" ++)) $ maybeFirst categories
 
-split :: Renderer leaf (IO TL.Text)
-split diff (before, after) = return . renderHtml
+split :: Renderer leaf TL.Text
+split diff (before, after) = renderHtml
   . docTypeHtml
     . ((head $ link ! A.rel "stylesheet" ! A.href "style.css") <>)
     . body