diff --git a/setup.py b/setup.py
index 7a7ad13e..f63f5ba0 100644
--- a/setup.py
+++ b/setup.py
@@ -44,7 +44,7 @@ except ImportError:
 # Take a look at https://www.python.org/dev/peps/pep-0440/
 # for a consistent versioning pattern.
 
-PSYCOPG_VERSION = '2.9.8'
+PSYCOPG_VERSION = '2.9.9.dev0'
 
 
 # note: if you are changing the list of supported Python version please fix