diff --git a/README.md b/README.md
index 2ca9c9e9..abb5d7b1 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@ Basic principles:
 
 ## Dependencies
 
-JupyterHub requires [IPython](https://ipython.org/install.html) >= 3.0 (current master) and [Python](https://www.python.org/downloads/) >= 3.3.
+JupyterHub itself requires [Python](https://www.python.org/downloads/) ≥ 3.3. To run the single-user servers (which may be on the same system as the Hub or not), [Jupyter Notebook](https://jupyter.readthedocs.org/en/latest/install.html) ≥ 4 is required.
 
 Install [nodejs/npm](https://www.npmjs.com/), which is available from your
 package manager. For example, install on Linux (Debian/Ubuntu) using:
@@ -50,14 +50,15 @@ Notes on the `pip` command used in the installation directions below:
 
 ## Installation
 
-JupyterHub can be installed with pip:
+JupyterHub can be installed with pip, and the proxy with npm:
 
+    npm install -g configurable-http-proxy
     pip3 install jupyterhub
 
 If you plan to run notebook servers locally, you may also need to install the
 Jupyter ~~IPython~~ notebook:
 
-    pip3 install notebook
+    pip3 install --upgrade notebook
 
 
 ### Development install
diff --git a/scripts/jupyterhub-singleuser b/scripts/jupyterhub-singleuser
old mode 100755
new mode 100644
index 21cc0ba2..11c60f5a
--- a/scripts/jupyterhub-singleuser
+++ b/scripts/jupyterhub-singleuser
@@ -17,34 +17,22 @@ from jinja2 import ChoiceLoader, FunctionLoader
 from tornado import ioloop
 from tornado.web import HTTPError
 
+try:
+    import notebook
+except ImportError:
+    raise ImportError("JupyterHub single-user server requires notebook >= 4.0")
 
-from IPython.utils.traitlets import (
+from traitlets import (
     Integer,
     Unicode,
     CUnicode,
 )
 
-try:
-    import notebook
-    # 4.x
-except ImportError:
-    from IPython.html.notebookapp import NotebookApp, aliases as notebook_aliases
-    from IPython.html.auth.login import LoginHandler
-    from IPython.html.auth.logout import LogoutHandler
+from notebook.notebookapp import NotebookApp, aliases as notebook_aliases
+from notebook.auth.login import LoginHandler
+from notebook.auth.logout import LogoutHandler
 
-    from IPython.html.utils import url_path_join
-
-    from distutils.version import LooseVersion as V
-
-    import IPython
-    if V(IPython.__version__) < V('3.0'):
-        raise ImportError("JupyterHub Requires IPython >= 3.0, found %s" % IPython.__version__)
-else:
-    from notebook.notebookapp import NotebookApp, aliases as notebook_aliases
-    from notebook.auth.login import LoginHandler
-    from notebook.auth.logout import LogoutHandler
-
-    from notebook.utils import url_path_join
+from notebook.utils import url_path_join
 
 
 # Define two methods to attach to AuthenticatedHandler,