diff --git a/src-literatetests/30-tests-context-free.blt b/src-literatetests/30-tests-context-free.blt
index d5c4507..6074d13 100644
--- a/src-literatetests/30-tests-context-free.blt
+++ b/src-literatetests/30-tests-context-free.blt
@@ -1163,6 +1163,12 @@ foo = Reflex.runSpiderHost $ ReflexHost.hostApp $ do
   liftIO . forkIO . forever $ getLine >>= inputFire
   ReflexHost.performEvent_ $ fmap (liftIO . putStrLn) inputEvent
 
+#test issue 15
+-- Test.hs
+module Test where
+
+data X = X
+
 #test issue 16
 foldrDesc f z = unSwitchQueue $ \q ->
   switch (Min.foldrDesc (f unTaggedF) z q) (Min.foldrAsc (f unTaggedF) z q)
diff --git a/src/Language/Haskell/Brittany/Internal/Layouters/DataDecl.hs b/src/Language/Haskell/Brittany/Internal/Layouters/DataDecl.hs
index 0102034..8820bda 100644
--- a/src/Language/Haskell/Brittany/Internal/Layouters/DataDecl.hs
+++ b/src/Language/Haskell/Brittany/Internal/Layouters/DataDecl.hs
@@ -39,96 +39,163 @@ layoutDataDecl
   -> HsDataDefn RdrName
   -> ToBriDocM BriDocNumbered
 layoutDataDecl ld name (HsQTvs _ bndrs _) defn = case defn of
+
   HsDataDefn NewType (L _ []) _ctype Nothing [cons] mDerivs -> case cons of
     (L _ (ConDeclH98 consName Nothing (Just (L _ [])) details _)) ->
       docWrapNode ld $ do
         nameStr     <- lrdrNameToTextAnn name
         consNameStr <- lrdrNameToTextAnn consName
-        tyVarDocs   <- bndrs `forM` \case
-          (L _ (UserTyVar vname)) -> return $ (lrdrNameToText vname, Nothing)
-          (L _ (KindedTyVar lrdrName kind)) -> do
-            d <- docSharedWrapper layoutType kind
-            return $ (lrdrNameToText lrdrName, Just $ d)
-        tyVarLine   <-
-          fmap return
-            $   docSeq
-            $   List.intersperse docSeparator
-            $   tyVarDocs
-            <&> \(vname, mKind) -> case mKind of
-                  Nothing   -> docLit vname
-                  Just kind -> docSeq
-                    [ docLit (Text.pack "(")
-                    , docLit vname
-                    , docSeparator
-                    , kind
-                    , docLit (Text.pack ")")
-                    ]
-        headDoc     <- fmap return $ docSeq
+        tyVarLine   <- fmap return $ createBndrDoc bndrs
+        -- headDoc     <- fmap return $ docSeq
+        --   [ appSep $ docLit (Text.pack "newtype")
+        --   , appSep $ docLit nameStr
+        --   , appSep tyVarLine
+        --   ]
+        rhsDoc      <- fmap return $ createDetailsDoc consNameStr details
+        createDerivingPar mDerivs $ docSeq
           [ appSep $ docLit (Text.pack "newtype")
           , appSep $ docLit nameStr
           , appSep tyVarLine
+          , docSeparator
+          , docLit (Text.pack "=")
+          , docSeparator
+          , rhsDoc
           ]
-        rhsDoc      <- fmap return $ case details of
-          PrefixCon args         -> docSeq
-            [ docLit consNameStr
-            , docSeparator
-            , docSeq $ List.intersperse docSeparator $ args <&> layoutType
-            ]
-          RecCon    (L _ fields) -> docSeq
-            [ appSep $ docLit $ Text.pack "{"
-            , docSeq
-              $   List.intersperse docSeparator
-              $   fields
-              <&> \(L _ (ConDeclField names t _)) -> do
-                    docSeq
-                      [ docSeq
-                        $   List.intersperse docCommaSep
-                        $   names
-                        <&> \(L _ (FieldOcc fieldName _)) ->
-                              docLit =<< lrdrNameToTextAnn fieldName
-                      , docSeparator
-                      , docLit $ Text.pack "::"
-                      , docSeparator
-                      , layoutType t
-                      ]
-            , docLit $ Text.pack "}"
-            ]
-          InfixCon arg1 arg2     -> docSeq
-            [ layoutType arg1
-            , docSeparator
-            , docLit consNameStr
-            , docSeparator
-            , layoutType arg2
-            ]
-        let
-          mainDoc =
-            docSeq
-              [ headDoc
-              , docSeparator
-              , docLit (Text.pack "=")
-              , docSeparator
-              , rhsDoc
-              ]
-        case mDerivs of
-          Nothing                 -> mainDoc
-          Just (L _ [(HsIB _ t)]) -> do
-            docAddBaseY BrIndentRegular $ docPar mainDoc $ docSeq
-              [docLit $ Text.pack "deriving", docSeparator, layoutType t]
-          Just (L _ ts          ) -> do
-            docAddBaseY BrIndentRegular $ docPar mainDoc $ docSeq
-              [ docLit $ Text.pack "deriving"
-              , docSeparator
-              , docLit $ Text.pack "("
-              , docSeq $ List.intersperse docCommaSep $ ts <&> \(HsIB _ t) ->
-                layoutType t
-              , docLit $ Text.pack ")"
-              ]
-    _ -> briDocByExactNoComment ld
+    _ -> briDocByExact ld
 
-  -- HsDataDefn DataType _ctxt _ctype Nothing _conss _derivs -> do
-  --   -- _ name vars ctxt ctype mKindSig conss derivs
-  --   nameStr <- lrdrNameToTextAnn name
-  --   docLit nameStr
+  HsDataDefn DataType (L _ lhsContext) _ctype Nothing [] mDerivs ->
+    docWrapNode ld $ do
+      lhsContextDoc <- docSharedWrapper createContextDoc lhsContext
+      nameStr       <- lrdrNameToTextAnn name
+      tyVarLine     <- fmap return $ createBndrDoc bndrs
+      createDerivingPar mDerivs $ docSeq
+        [ appSep $ docLit (Text.pack "data")
+        , lhsContextDoc
+        , appSep $ docLit nameStr
+        , appSep tyVarLine
+        ]
+
+  HsDataDefn DataType (L _ lhsContext) _ctype Nothing [cons] mDerivs ->
+    case cons of
+      (L _ (ConDeclH98 consName mForall mRhsContext details _)) ->
+        docWrapNode ld $ do
+          lhsContextDoc <- docSharedWrapper createContextDoc lhsContext
+          nameStr       <- lrdrNameToTextAnn name
+          consNameStr   <- lrdrNameToTextAnn consName
+          tyVarLine     <- fmap return $ createBndrDoc bndrs
+          forallDoc     <- docSharedWrapper createForallDoc mForall
+          rhsContextDoc <- case mRhsContext of
+            Nothing         -> return docEmpty
+            Just (L _ ctxt) -> docSharedWrapper createContextDoc ctxt
+          rhsDoc        <- fmap return $ createDetailsDoc consNameStr details
+          createDerivingPar mDerivs $ docSeq
+            [ appSep $ docLit (Text.pack "data")
+            , lhsContextDoc
+            , appSep $ docLit nameStr
+            , appSep tyVarLine
+            , docSeparator
+            , docLit (Text.pack "=")
+            , docSeparator
+            , forallDoc
+            , rhsContextDoc
+            , rhsDoc
+            ]
+      _ -> briDocByExact ld
 
   _ -> briDocByExactNoComment ld
+ where
+  createContextDoc :: HsContext RdrName -> ToBriDocM BriDocNumbered
+  createContextDoc [] = docEmpty
+  createContextDoc [t] =
+    docSeq [layoutType t, docSeparator, docLit (Text.pack "=>"), docSeparator]
+  createContextDoc ts = docSeq
+    [ docLit (Text.pack "(")
+    , docSeq $ List.intersperse docCommaSep (layoutType <$> ts)
+    , docLit (Text.pack ") =>")
+    , docSeparator
+    ]
+  createBndrDoc :: [LHsTyVarBndr RdrName] -> ToBriDocM BriDocNumbered
+  createBndrDoc bs = do
+    tyVarDocs <- bs `forM` \case
+      (L _ (UserTyVar vname)) -> return $ (lrdrNameToText vname, Nothing)
+      (L _ (KindedTyVar lrdrName kind)) -> do
+        d <- docSharedWrapper layoutType kind
+        return $ (lrdrNameToText lrdrName, Just $ d)
+    docSeq
+      $   List.intersperse docSeparator
+      $   tyVarDocs
+      <&> \(vname, mKind) -> case mKind of
+            Nothing   -> docLit vname
+            Just kind -> docSeq
+              [ docLit (Text.pack "(")
+              , docLit vname
+              , docSeparator
+              , docLit (Text.pack "::")
+              , docSeparator
+              , kind
+              , docLit (Text.pack ")")
+              ]
+  createDerivingPar
+    :: HsDeriving RdrName
+    -> ToBriDocM BriDocNumbered
+    -> ToBriDocM BriDocNumbered
+  createDerivingPar mDerivs mainDoc = do
+    case mDerivs of
+      Nothing                 -> docLines [mainDoc]
+      Just (L _ [(HsIB _ t)]) -> do
+        docAddBaseY BrIndentRegular $ docPar mainDoc $ docSeq
+          [docLit $ Text.pack "deriving", docSeparator, layoutType t]
+      Just (L _ ts          ) -> do
+        docAddBaseY BrIndentRegular $ docPar mainDoc $ docSeq
+          [ docLit $ Text.pack "deriving"
+          , docSeparator
+          , docLit $ Text.pack "("
+          , docSeq $ List.intersperse docCommaSep $ ts <&> \(HsIB _ t) ->
+            layoutType t
+          , docLit $ Text.pack ")"
+          ]
+  createDetailsDoc
+    :: Text -> HsConDeclDetails RdrName -> (ToBriDocM BriDocNumbered)
+  createDetailsDoc consNameStr details = case details of
+    PrefixCon args         -> docSeq
+      [ docLit consNameStr
+      , docSeparator
+      , docSeq $ List.intersperse docSeparator $ args <&> layoutType
+      ]
+    RecCon    (L _ fields) -> docSeq
+      [ appSep $ docLit $ Text.pack "{"
+      , docSeq
+        $   List.intersperse docSeparator
+        $   fields
+        <&> \(L _ (ConDeclField names t _)) -> do
+              docSeq
+                [ docSeq
+                  $   List.intersperse docCommaSep
+                  $   names
+                  <&> \(L _ (FieldOcc fieldName _)) ->
+                        docLit =<< lrdrNameToTextAnn fieldName
+                , docSeparator
+                , docLit $ Text.pack "::"
+                , docSeparator
+                , layoutType t
+                ]
+      , docLit $ Text.pack "}"
+      ]
+    InfixCon arg1 arg2     -> docSeq
+      [ layoutType arg1
+      , docSeparator
+      , docLit consNameStr
+      , docSeparator
+      , layoutType arg2
+      ]
+  createForallDoc :: Maybe (LHsQTyVars RdrName) -> ToBriDocM BriDocNumbered
+  createForallDoc Nothing                   = docEmpty
+  createForallDoc (Just (HsQTvs _ bs _)) = do
+    tDoc <- fmap return $ createBndrDoc bs
+    docSeq
+      [ docLit (Text.pack "forall ")
+      , tDoc
+      , docLit (Text.pack " .")
+      , docSeparator
+      ]