diff --git a/pyproject.toml b/pyproject.toml
index 19fd732..0b40501 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "attpc_engine"
-version = "0.8.0"
+version = "0.9.0rc0"
 description = "AT-TPC Monte-Carlo simulation engine"
 authors = [
     {name = "Gordon McCann", email = "gordonmccann215@gmail.com"},