diff --git a/flask/__init__.py b/flask/__init__.py
index b3b009b69e..268ecd0bef 100644
--- a/flask/__init__.py
+++ b/flask/__init__.py
@@ -10,7 +10,7 @@
     :license: BSD, see LICENSE for more details.
 """
 
-__version__ = '0.12.3'
+__version__ = '0.12.4.dev'
 
 # utilities we import from Werkzeug and Jinja2 that are unused
 # in the module but are exported as public interface.