     end
   end
 
+  {:ok, req} = Version.parse_requirement("< 1.4.0")
+  if Version.match?(Version.parse!(System.version), req) do
+    @time_unit :milliseconds
+  else
+    @time_unit :millisecond
+  end
+
   # Wait for VM and application to start
   defp wait_for_app(bin_path) do
     parent = self()

      {:ok, :pong} ->
        :ok
      _other ->
        ts = System.monotonic_time(:millisecond)
        do_wait_for_app(pid, time_remaining - (ts - start))
    after
      time_remaining ->

    :timeout
  end
  defp do_wait_for_app(pid, time_remaining) do
    start = System.monotonic_time(@time_unit)
    if System.get_env("VERBOSE_TESTS") do
      IO.puts "Waiting #{time_remaining}ms for app.."
    end
