diff --git a/CHANGELOG.md b/CHANGELOG.md
index 77afc7d..9fa5325 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # Refract Python Changelog
 
-## Master
+## 0.4.0 (2019-04-08)
 
 ### Breaking
 
diff --git a/docs/conf.py b/docs/conf.py
index 1bc3708..5c8e667 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -56,9 +56,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = '0.3'
+version = '0.4'
 # The full version, including alpha/beta/rc tags.
-release = '0.3.1'
+release = '0.4.0'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/setup.py b/setup.py
index 62da331..6d07b73 100644
--- a/setup.py
+++ b/setup.py
@@ -4,7 +4,7 @@
 
 setup(
     name='refract',
-    version='0.3.1',
+    version='0.4.0',
     description='A Python library for interacting with Refract.',
     url='https://github.com/kylef/refract.py',
     packages=['refract', 'refract.elements', 'refract.contrib'],