diff --git a/CHANGES.rst b/CHANGES.rst
index 9cdce21..1f00e81 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,6 +1,10 @@
 Change Log
 ==========
 
+2.6.4 (unreleased)
+------------------
+
+
 2.6.3 (2021-06-08)
 ------------------
 
diff --git a/version.txt b/version.txt
index ec1cf33..5e85526 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-2.6.3
+2.6.4.dev0