diff --git a/notebook/_version.py b/notebook/_version.py
index a71441813..bc030fd36 100644
--- a/notebook/_version.py
+++ b/notebook/_version.py
@@ -1,2 +1,2 @@
-version_info = (4, 0, 1)
+version_info = (4, 1, 0, 'dev')
 __version__ = '.'.join(map(str, version_info))
diff --git a/notebook/static/base/js/namespace.js b/notebook/static/base/js/namespace.js
index 50e1965a1..e9e4183f3 100644
--- a/notebook/static/base/js/namespace.js
+++ b/notebook/static/base/js/namespace.js
@@ -75,7 +75,7 @@ define(function(){
     jglobal('ClusterList','tree/js/clusterlist');
     jglobal('ClusterItem','tree/js/clusterlist');
 
-    Jupyter.version = "4.0.1";
+    Jupyter.version = "4.1.0.dev";
     Jupyter._target = '_blank';
     return Jupyter;
 });