diff --git a/pyproject.toml b/pyproject.toml
index c99cea84462588d5ed74b6af14f4bbedb5edce82..11198afffae7a2c5d65ddb07343056fc807cccfe 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "icartt"
-version = "1.9.1"
+version = "2.0.0-rc1"
 description = "ICARTT format reader and writer"
 license = "GPL-3.0-or-later"
 authors = ["Christoph Knote <christoph.knote@med.uni-augsburg.de>"]