diff --git a/js/package.json b/js/package.json
index a72e2641..4339ff80 100644
--- a/js/package.json
+++ b/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "jupyter-threejs",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "description": "jupyter - threejs bridge",
   "author": "Jupyter-Threejs development team",
   "license": "BSD-3-Clause",
@@ -21,7 +21,10 @@
   "dependencies": {
     "@jupyter-widgets/base": "^1.0.0",
     "ndarray": "^1.0.18",
-    "three": "^0.75.0",
+    "three": "^0.85.0",
     "underscore": "^1.8.3"
+  },
+  "jupyterlab": {
+    "extension": "src/jupyterlab-plugin"
   }
 }
diff --git a/jslab/lib/index.js b/js/src/jupyterlab-plugin.js
similarity index 61%
rename from jslab/lib/index.js
rename to js/src/jupyterlab-plugin.js
index 4f54332f..8bab62bf 100644
--- a/jslab/lib/index.js
+++ b/js/src/jupyterlab-plugin.js
@@ -1,10 +1,10 @@
-var jupyter_threejs = require('jupyter-threejs');
+var jupyter_threejs = require('./index');
 
-var jupyterlab_widgets = require('@jupyter-widgets/jupyterlab-manager');
+var base = require('@jupyter-widgets/base');
 
 module.exports = {
   id: 'jupyter.extensions.jupyter-threejs',
-  requires: [jupyterlab_widgets.INBWidgetExtension],
+  requires: [base.IJupyterWidgetRegistry],
   activate: function(app, widgets) {
       widgets.registerWidget({
           name: 'jupyter-threejs',
diff --git a/jslab/package.json b/jslab/package.json
deleted file mode 100644
index 1e31c43d..00000000
--- a/jslab/package.json
+++ /dev/null
@@ -1,18 +0,0 @@
-{
-  "name": "jupyterlab-threejs",
-  "version": "0.2.0",
-  "description": "",
-  "main": "lib/index.js",
-  "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
-  },
-  "author": "jupyterlab-threejs developers",
-  "license": "BSD-3-Clause",
-  "dependencies": {
-    "@jupyter-widgets/jupyterlab-manager": "^0.27.0",
-    "jupyter-threejs": "^0.4.0"
-  },
-  "jupyterlab": {
-    "extension": true
-  }
-}
diff --git a/pythreejs/_version.py b/pythreejs/_version.py
index 713e923d..aa465eac 100644
--- a/pythreejs/_version.py
+++ b/pythreejs/_version.py
@@ -1,8 +1,8 @@
-version_info = (0, 4, 0, 'final', 0)
+version_info = (0, 4, 2, 'final', 0)
 
 _specifier_ = {'alpha': 'a', 'beta': 'b', 'candidate': 'rc', 'final': ''}
 
 __version__ = '%s.%s.%s%s'%(version_info[0], version_info[1], version_info[2],
           '' if version_info[3]=='final' else _specifier_[version_info[3]]+str(version_info[4]))
 
-EXTENSION_VERSION = '0.4.0'
+EXTENSION_VERSION = '0.4.1'
diff --git a/pythreejs/pythreejs.py b/pythreejs/pythreejs.py
index 922c11ab..d56cba7e 100644
--- a/pythreejs/pythreejs.py
+++ b/pythreejs/pythreejs.py
@@ -38,7 +38,7 @@ def vector2(trait_type=CFloat, default=None, **kwargs):
         default = [0, 0]
     return List(trait_type, default_value=default, minlen=2, maxlen=2, **kwargs)
 
-PYTHREEJS_VERSION='0.3.0-alpha.0'
+PYTHREEJS_VERSION='0.4.1'
 
 class Texture(Widget):
     _view_module = Unicode(npm_pkg_name).tag(sync=True)
diff --git a/setup.py b/setup.py
index cbe5d281..091240d5 100644
--- a/setup.py
+++ b/setup.py
@@ -48,7 +48,7 @@
             'pythreejs/static/index.js.map',
         ]),
     ],
-    'install_requires': ['ipywidgets>=7,<8', 'traittypes'],
+    'install_requires': ['ipywidgets>=7,<8', 'numpy', 'traittypes'],
     'packages': find_packages(),
     'zip_safe': False,
     'cmdclass': cmdclass,