diff --git a/cobalt/__init__.py b/cobalt/__init__.py
index caeba1c..cae7f64 100644
--- a/cobalt/__init__.py
+++ b/cobalt/__init__.py
@@ -8,7 +8,7 @@
 from .portion import PortionStructure, Portion
 from .uri import FrbrUri
 
-__version__ = '9.0.0'
+__version__ = '9.0.1'
 
 __all__ = [
     'Act', 'AkomaNtosoDocument', 'Amendment', 'AmendmentEvent', 'AmendmentList', 'AmendmentStructure',