diff --git a/notebook/_version.py b/notebook/_version.py
index afb6fd217d..065fa2c3f7 100644
--- a/notebook/_version.py
+++ b/notebook/_version.py
@@ -13,5 +13,5 @@
     version_info.minor,
     version_info.micro,
     version_info.releaselevel,
-    version_info.serial
+    version_info.serial,
 )