diff --git a/bonobo/_version.py b/bonobo/_version.py
index 63f9f1e..0520fdb 100644
--- a/bonobo/_version.py
+++ b/bonobo/_version.py
@@ -1 +1 @@
-__version__ = '0.6.0a4'
+__version__ = '0.6.0b1'