diff --git a/mix.exs b/mix.exs
index 5c44fb5..2188c26 100644
--- a/mix.exs
+++ b/mix.exs
@@ -4,7 +4,7 @@ defmodule Koans.Mixfile do
   def project do
     [app: :elixir_koans,
      version: "0.0.1",
-     elixir: ">= 1.2.1 and < 1.4.0",
+     elixir: ">= 1.2.1 and <= 1.4.0",
      elixirc_paths: elixirc_path(Mix.env),
      deps: deps]
   end