diff --git a/src/emsgpack.app.src b/src/emsgpack.app.src
index c934d90..352daa8 100644
--- a/src/emsgpack.app.src
+++ b/src/emsgpack.app.src
@@ -1,5 +1,5 @@
 {application, emsgpack, [{description, "Erlang MessagePack library"},
-                         {vsn, "0.3.0"},
+                         {vsn, "0.4.0"},
                          {registered, []},
                          {applications, [kernel, stdlib]},
                          {modules, []},