Listing all the files under a directory recursively, using Pipes

I finished reading the Pipes tutorial, and I wanted to write a function to list all the files in a directory, recursively. I tried with the following code:

enumFiles :: FilePath -> Producer' FilePath (PS.SafeT IO) ()
enumFiles path =
  PS.bracket (openDirStream path) (closeDirStream) loop
  where
    loop :: DirStream -> Producer' FilePath (PS.SafeT IO) ()
    loop ds = PS.liftBase (readDirStream ds) >>= checkName
      where
        checkName :: FilePath -> Producer' FilePath (PS.SafeT IO) ()
        checkName ""   = return ()
        checkName "."  = loop ds
        checkName ".." = loop ds
        checkName name = PS.liftBase (getSymbolicLinkStatus newPath)
                         >>= checkStat newPath
          where newPath = path </> name

        checkStat path stat
          | isRegularFile stat = yield path >> loop ds
          | isDirectory stat = enumFiles path
          | otherwise = loop ds

However this producer will terminate as soon as the return () is reached. I guess I'm not composing it in the right way, but I fail to see what is the correct way of doing this.