diff --git a/implementations/python/setup.py b/implementations/python/setup.py
index 249c5d3..2afb8f3 100644
--- a/implementations/python/setup.py
+++ b/implementations/python/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup
 
 setup(
     name="preserves",
-    version="0.990.1",
+    version="0.991.0",
     author="Tony Garnock-Jones",
     author_email="tonyg@leastfixedpoint.com",
     license="Apache Software License",