diff --git a/pyproject.toml b/pyproject.toml
index f47b0ff..6329d18 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,7 +7,7 @@ packages = []
 
 [project]
 name = "python-bsonjs"
-version = "0.5.0"
+version = "0.6.0.dev0"
 description = "A library for converting between BSON and JSON."
 readme = "README.rst"
 license = { file = "LICENSE" }