level: TypeError: exists is not a function

Hi, I’m getting this error when using Level.

Console shows the error here, which is in bindings module:

exports.getRoot = function getRoot (file) {
  var dir = dirname(file)
    , prev
  while (true) {
    if (dir === '.') {
      // Avoids an infinite loop in rare cases, like the REPL
      dir = process.cwd()
    }
    if (exists(join(dir, 'package.json')) || exists(join(dir, 'node_modules'))) {
      // Found the 'package.json' file or 'node_modules' dir; we're done
      return dir
    }