diff --git a/docs/changelog.md b/docs/changelog.md
index f40a79fd..875159bb 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## 0.4.0 (unreleased)
+
+### Major Changes
+
+- Mimic an Output widget at the frontend so that the Output widget behaves correctly [#68](https://github.com/jupyter/nbclient/pull/68)
+
 ## 0.3.1
 
 ### Fixes
diff --git a/nbclient/_version.py b/nbclient/_version.py
index 2e20de5d..a9731bad 100644
--- a/nbclient/_version.py
+++ b/nbclient/_version.py
@@ -1 +1 @@
-version = '0.3.1'
+version = '0.4.0-dev.0'