diff --git a/mix.exs b/mix.exs
index 9e10cfab..ed2034c2 100644
--- a/mix.exs
+++ b/mix.exs
@@ -2,7 +2,7 @@ defmodule Protobuf.Mixfile do
   use Mix.Project
 
   @source_url "https://github.com/elixir-protobuf/protobuf"
-  @version "0.13.0"
+  @version "0.12.0"
   @description "A pure Elixir implementation of Google Protobuf."
 
   def project do