diff --git a/httptools/_version.py b/httptools/_version.py
index d49ea6f..f1999b3 100644
--- a/httptools/_version.py
+++ b/httptools/_version.py
@@ -10,4 +10,4 @@
 # supported platforms, publish the packages on PyPI, merge the PR
 # to the target branch, create a Git tag pointing to the commit.
 
-__version__ = '0.6.4'
+__version__ = '0.7.0.dev0'