diff --git a/IPython/html/services/notebooks/filenbmanager.py b/IPython/html/services/notebooks/filenbmanager.py
index c64cc5a..9f93f95 100644
--- a/IPython/html/services/notebooks/filenbmanager.py
+++ b/IPython/html/services/notebooks/filenbmanager.py
@@ -100,7 +100,7 @@ class FileNotebookManager(NotebookManager):
full_path = self.get_path(notebook_name, notebook_path)
if change == "name":
new_path = self.get_path(data['name'], notebook_path)
- if os.path.isfile(new_path) == False:
+ if not os.path.isfile(new_path):
os.rename(full_path,
self.get_path(data['name'], notebook_path))
notebook_name = data['name']