Template Haskell: Generate unique data type names

Error message

ghci -ddump-splices test2.hs                                                                                                                                                 12:17:44
GHCi, version 7.6.3: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
[1 of 2] Compiling THTest           ( THTest.hs, interpreted )
[2 of 2] Compiling Test             ( test2.hs, interpreted )
Loading package array-0.4.0.1 ... linking ... done.
Loading package deepseq-1.3.0.1 ... linking ... done.
Loading package containers-0.5.0.0 ... linking ... done.
Loading package pretty-1.1.1.0 ... linking ... done.
Loading package template-haskell ... linking ... done.
test2.hs:1:1: Splicing declarations
    spliceDataDecs
  ======>
    test2.hs:6:1-14
    data EmptyData_a152
test2.hs:1:1: Splicing declarations
    spliceDataDecs
  ======>
    test2.hs:7:1-14
    data EmptyData_a156

test2.hs:7:1:
    Multiple declarations of `EmptyData'
    Declared at: test2.hs:6:1
                 test2.hs:7:1
Failed, modules loaded: THTest.

test.hs

{-# LANGUAGE TemplateHaskell #-}
module Test where

import THTest

spliceDataDecs
spliceDataDecs

THTest.hs

module THTest where

import Language.Haskell.TH
import Control.Monad

spliceDataDecs :: Q [Dec]
spliceDataDecs = do
  names <- replicateM 1 $ newName "EmptyData"
  return $ map (\n -> DataD [] n [] [] []) names