diff --git a/tarpc/Cargo.toml b/tarpc/Cargo.toml
index 43e6235..9208725 100644
--- a/tarpc/Cargo.toml
+++ b/tarpc/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "tarpc"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Adam Wright <adam.austin.wright@gmail.com>", "Tim Kuehn <timothy.j.kuehn@gmail.com>"]
 license = "MIT"
 documentation = "https://google.github.io/tarpc"