diff --git a/curvesim/version.py b/curvesim/version.py
index 5176234dd..16a8769dd 100644
--- a/curvesim/version.py
+++ b/curvesim/version.py
@@ -6,7 +6,7 @@
 """
 import re
 
-__version__ = "0.4.5"
+__version__ = "0.5.0.b1"
 
 
 def parse_version(version):
diff --git a/setup.cfg b/setup.cfg
index 846c8fae5..a7bad4ded 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 0.4.5
+current_version = 0.5.0.b1
 parse = (?P<major>\d+)\.(?P<minor>\d+)\.(?P<patch>\d+)(\.(?P<release>.*)(?P<build>\d+))?
 serialize = 
 	{major}.{minor}.{patch}.{release}{build}