diff --git a/Cargo.toml b/Cargo.toml
index 185fd93..736e9f8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,7 +10,7 @@ default-members = [".", "members/libpt-core"]
 
 [workspace.package]
 publish = true
-version = "0.3.12"
+version = "0.4.0.alpha.1"
 edition = "2021"
 authors = ["Christoph J. Scherr <software@cscherr.de>"]
 license = "MIT"