diff --git a/Yesod/Hamlet.hs b/Yesod/Hamlet.hs
index 01ced745..e8947155 100644
--- a/Yesod/Hamlet.hs
+++ b/Yesod/Hamlet.hs
@@ -15,8 +15,6 @@ module Yesod.Hamlet
     , hamletToRepHtml
       -- * Page templates
     , PageContent (..)
-      -- * data-object
-    , HtmlObject
     )
     where
 
@@ -25,8 +23,6 @@ import Text.Hamlet.Monad (outputHtml)
 import Yesod.Content
 import Yesod.Handler
 import Data.Convertible.Text
-import Data.Object -- FIXME should we kill this?
-import Control.Arrow ((***))
 import Web.Routes.Quasi (Routes)
 import Data.Text (Text)
 import Web.Encodings (encodeHtml)
@@ -65,27 +61,5 @@ hamletToRepHtml = fmap RepHtml . hamletToContent
 
 instance Monad m => ConvertSuccess String (Hamlet url m ()) where
     convertSuccess = outputHtml . Unencoded . cs
-instance Monad m
-    => ConvertSuccess (Object String HtmlContent) (Hamlet url m ()) where
-    convertSuccess (Scalar h) = outputHtml h
-    convertSuccess (Sequence s) = template () where
-        template = [$hamlet|
-                %ul
-                    $forall s' s
-                        %li ^s^|]
-        s' _ = map cs s
-    convertSuccess (Mapping m) = template () where
-        template :: Monad m => () -> Hamlet url m ()
-        template = [$hamlet|
-                %dl
-                    $forall pairs pair
-                        %dt $pair.fst$
-                        %dd ^pair.snd^|]
-        pairs _ = map (cs *** cs) m
 instance ConvertSuccess String HtmlContent where
     convertSuccess = Unencoded . cs
-
-type HtmlObject = Object String HtmlContent
-
-instance ConvertSuccess (Object String String) HtmlObject where
-    convertSuccess = fmap cs
diff --git a/Yesod/Json.hs b/Yesod/Json.hs
index 8cb6f10b..44b56fc5 100644
--- a/Yesod/Json.hs
+++ b/Yesod/Json.hs
@@ -73,7 +73,7 @@ jsonList :: [Json url ()] -> Json url ()
 jsonList = jsonList' . fromList
 
 -- | Same as 'jsonList', but uses an 'Enumerator' for input.
-jsonList' :: Enumerator (Json url ()) (Json url) -> Json url () -- FIXME simplify type
+jsonList' :: Enumerator (Json url ()) (Json url) -> Json url ()
 jsonList' (Enumerator enum) = do
     Json $ outputString "["
     _ <- enum go False
@@ -89,7 +89,7 @@ jsonMap :: [(String, Json url ())] -> Json url ()
 jsonMap = jsonMap' . fromList
 
 -- | Same as 'jsonMap', but uses an 'Enumerator' for input.
-jsonMap' :: Enumerator (String, Json url ()) (Json url) -> Json url () -- FIXME simplify type
+jsonMap' :: Enumerator (String, Json url ()) (Json url) -> Json url ()
 jsonMap' (Enumerator enum) = do
     Json $ outputString "{"
     _ <- enum go False
diff --git a/yesod.cabal b/yesod.cabal
index 8b140bd4..9a86a6b1 100644
--- a/yesod.cabal
+++ b/yesod.cabal
@@ -23,7 +23,6 @@ library
                      authenticate >= 0.6 && < 0.7,
                      bytestring >= 0.9.1.4 && < 0.10,
                      web-encodings >= 0.2.4 && < 0.3,
-                     data-object >= 0.2.0 && < 0.3,
                      directory >= 1 && < 1.1,
                      control-monad-attempt >= 0.2.0 && < 0.3,
                      text >= 0.5 && < 0.8,