diff --git a/setup.py b/setup.py
index 9bf61e65..c370b19b 100755
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@
 labext_name = "rise-jupyterlab"
 
 INSTALL_REQUIRES = [
-    "jupyter_server>=1.6,<2"
+    "jupyter_server>=1.6,<2",
     "jupyterlab>=3,<4"
 ]