diff --git a/pyproject.toml b/pyproject.toml
index 05cc03c..124de57 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,7 +5,7 @@ build-backend = "flit_core.buildapi"
 [project]
 name = "natlinkcore"
 authors = [{name = "Quintijn Hoogenboom (maintainer)", email = "q.hoogenboom@antenna.nl"}]
-version="5.5a1.dev1"
+version="5.4.2.dev1"
 dynamic = [ "description"]
 requires-python = ">=3.9"
 readme = "readme.md"