diff --git a/IPython/html/base/handlers.py b/IPython/html/base/handlers.py
index e9b9c85..8d67501 100644
--- a/IPython/html/base/handlers.py
+++ b/IPython/html/base/handlers.py
@@ -299,7 +299,7 @@ class AuthenticatedFileHandler(IPythonHandler, web.StaticFileHandler):
         or the UF_HIDDEN flag as reported by stat
         """
         inside_root = absolute_path[len(absolute_root):]
-        if any(part.startswith('.') for part in inside_root.split(os.path.sep)):
+        if any(part.startswith('.') for part in inside_root.split(os.sep)):
             raise web.HTTPError(403)
         
         # check UF_HIDDEN on any location up to root
@@ -367,7 +367,7 @@ class FileFindHandler(web.StaticFileHandler):
         if isinstance(path, basestring):
             path = [path]
         self.roots = tuple(
-            os.path.abspath(os.path.expanduser(p)) + os.path.sep for p in path
+            os.path.abspath(os.path.expanduser(p)) + os.sep for p in path
         )
         self.default_filename = default_filename
     
@@ -385,7 +385,7 @@ class FileFindHandler(web.StaticFileHandler):
         
             # os.path.abspath strips a trailing /
             # it needs to be temporarily added back for requests to root/
-            if not (abspath + os.path.sep).startswith(roots):
+            if not (abspath + os.sep).startswith(roots):
                 raise HTTPError(403, "%s is not in root static directory", path)
         
             cls._static_paths[path] = abspath
@@ -470,7 +470,7 @@ class FileFindHandler(web.StaticFileHandler):
         if isinstance(static_paths, basestring):
             static_paths = [static_paths]
         roots = tuple(
-            os.path.abspath(os.path.expanduser(p)) + os.path.sep for p in static_paths
+            os.path.abspath(os.path.expanduser(p)) + os.sep for p in static_paths
         )
 
         try:
@@ -504,8 +504,8 @@ class FileFindHandler(web.StaticFileHandler):
         ``static_url_prefix`` removed.  The return value should be
         filesystem path relative to ``static_path``.
         """
-        if os.path.sep != "/":
-            url_path = url_path.replace("/", os.path.sep)
+        if os.sep != "/":
+            url_path = url_path.replace("/", os.sep)
         return url_path
 
 class TrailingSlashHandler(web.RequestHandler):
diff --git a/IPython/html/services/notebooks/tests/test_notebooks_api.py b/IPython/html/services/notebooks/tests/test_notebooks_api.py
index c75903a..33238bc 100644
--- a/IPython/html/services/notebooks/tests/test_notebooks_api.py
+++ b/IPython/html/services/notebooks/tests/test_notebooks_api.py
@@ -102,12 +102,12 @@ class APITest(NotebookTestBase):
         nbdir = self.notebook_dir.name
 
         for d in self.dirs:
-            d.replace('/', os.path.sep)
+            d.replace('/', os.sep)
             if not os.path.isdir(pjoin(nbdir, d)):
                 os.mkdir(pjoin(nbdir, d))
 
         for d, name in self.dirs_nbs:
-            d = d.replace('/', os.path.sep)
+            d = d.replace('/', os.sep)
             with io.open(pjoin(nbdir, d, '%s.ipynb' % name), 'w') as f:
                 nb = new_notebook(name=name)
                 write(nb, f, format='ipynb')
@@ -172,7 +172,7 @@ class APITest(NotebookTestBase):
         self.assertEqual(resp.json()['name'], name)
         assert os.path.isfile(pjoin(
             self.notebook_dir.name,
-            path.replace('/', os.path.sep),
+            path.replace('/', os.sep),
             name,
         ))
 
diff --git a/IPython/html/tests/test_files.py b/IPython/html/tests/test_files.py
index cdc3cc1..78de40c 100644
--- a/IPython/html/tests/test_files.py
+++ b/IPython/html/tests/test_files.py
@@ -27,7 +27,7 @@ class FilesTest(NotebookTestBase):
         
         nbdir = self.notebook_dir.name
         for d in dirs:
-            path = pjoin(nbdir, d.replace('/', os.path.sep))
+            path = pjoin(nbdir, d.replace('/', os.sep))
             if not os.path.exists(path):
                 os.mkdir(path)
             with open(pjoin(path, 'foo'), 'w') as f:
@@ -37,7 +37,7 @@ class FilesTest(NotebookTestBase):
         url = self.base_url()
         
         for d in not_hidden:
-            path = pjoin(nbdir, d.replace('/', os.path.sep))
+            path = pjoin(nbdir, d.replace('/', os.sep))
             r = requests.get(url_path_join(url, 'files', d, 'foo'))
             r.raise_for_status()
             self.assertEqual(r.content, b'foo')
@@ -45,7 +45,7 @@ class FilesTest(NotebookTestBase):
             self.assertEqual(r.status_code, 403)
             
         for d in hidden:
-            path = pjoin(nbdir, d.replace('/', os.path.sep))
+            path = pjoin(nbdir, d.replace('/', os.sep))
             for foo in ('foo', '.foo'):
                 r = requests.get(url_path_join(url, 'files', d, foo))
                 self.assertEqual(r.status_code, 403)
diff --git a/IPython/html/utils.py b/IPython/html/utils.py
index 18a7941..7748de9 100644
--- a/IPython/html/utils.py
+++ b/IPython/html/utils.py
@@ -38,7 +38,7 @@ def url_path_join(*pieces):
 
 def path2url(path):
     """Convert a local file path to a URL"""
-    pieces = [ quote(p) for p in path.split(os.path.sep) ]
+    pieces = [ quote(p) for p in path.split(os.sep) ]
     # preserve trailing /
     if pieces[-1] == '':
         pieces[-1] = '/'