diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 1aa2131..65dfebe 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,6 +1,12 @@
 Changelog
 =========
 
+1.5 - `master`_
+~~~~~~~~~~~~~~~
+
+.. note:: This version is not yet released and is under active development.
+
+
 1.4 - 2016-06-04
 ~~~~~~~~~~~~~~~~
 
diff --git a/src/cryptography/__about__.py b/src/cryptography/__about__.py
index dc7c412..15ed36d 100644
--- a/src/cryptography/__about__.py
+++ b/src/cryptography/__about__.py
@@ -14,7 +14,7 @@
                " and primitives to Python developers.")
 __uri__ = "https://github.com/pyca/cryptography"
 
-__version__ = "1.4"
+__version__ = "1.5.dev1"
 
 __author__ = "The cryptography developers"
 __email__ = "cryptography-dev@python.org"
diff --git a/vectors/cryptography_vectors/__about__.py b/vectors/cryptography_vectors/__about__.py
index 5d90e88..f756b9d 100644
--- a/vectors/cryptography_vectors/__about__.py
+++ b/vectors/cryptography_vectors/__about__.py
@@ -14,7 +14,7 @@
 
 __uri__ = "https://github.com/pyca/cryptography"
 
-__version__ = "1.4"
+__version__ = "1.5.dev1"
 
 __author__ = "The cryptography developers"
 __email__ = "cryptography-dev@python.org"