diff --git a/Changelog.md b/Changelog.md
index 06bd36c..8d8a6b2 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,5 +1,9 @@
 # CHANGELOG
 
+## master (unreleased)
+
+Nothing here yet.
+
 ## v9.0.1 (2020-05-22)
 
 - Making the Israel calendar more efficient (#498).
diff --git a/setup.py b/setup.py
index e53f3a6..54ca66e 100644
--- a/setup.py
+++ b/setup.py
@@ -28,7 +28,7 @@ REQUIREMENTS = [
     'pyluach',
     'setuptools>=1.0',
 ]
-version = '9.0.1'
+version = '9.1.0.dev1'
 __VERSION__ = version
 
 params = dict(