diff --git a/setup.py b/setup.py
index 6ac739be..f575fa0a 100644
--- a/setup.py
+++ b/setup.py
@@ -72,7 +72,7 @@
         'ipykernel>=4.1', # not a real dependency, but require the reference kernel
         'qtpy>=2.4.0',
         'pyzmq>=17.1',
-        'packaging'
+        'packaging',
         'tornado==6.3.3'
     ],
     extras_require = {