diff --git a/IPython/core/release.py b/IPython/core/release.py
index fc955c9..9e22b03 100644
--- a/IPython/core/release.py
+++ b/IPython/core/release.py
@@ -20,11 +20,11 @@ name = 'ipython'
 # release.  'dev' as a _version_extra string means this is a development
 # version
 _version_major = 4
-_version_minor = 0
+_version_minor = 1
 _version_patch = 0
-# _version_extra = 'dev'
+_version_extra = 'dev'
 # _version_extra = 'rc1'
-_version_extra = ''  # Uncomment this for full releases
+# _version_extra = ''  # Uncomment this for full releases
 
 # release.codename is deprecated in 2.0, will be removed in 3.0
 codename = ''