diff --git a/Cargo.toml b/Cargo.toml
index bad3ed0..bfa5ee1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "mlua"
-version = "0.3.2"
+version = "0.4.0-beta.1"
 authors = ["Aleksandr Orlenko <zxteam@pm.me>", "kyren <catherine@chucklefish.org>"]
 edition = "2018"
 repository = "https://github.com/khvzak/mlua"
diff --git a/mlua_derive/Cargo.toml b/mlua_derive/Cargo.toml
index 3877447..2e5f138 100644
--- a/mlua_derive/Cargo.toml
+++ b/mlua_derive/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "mlua_derive"
-version = "0.3.0"
+version = "0.4.0-beta.1"
 authors = ["Aleksandr Orlenko <zxteam@pm.me>"]
 edition = "2018"
 description = "Procedural macros for the mlua crate."