diff --git a/pkgs/development/python-modules/notebook/default.nix b/pkgs/development/python-modules/notebook/default.nix
index d7232e58ceb..04fe19377f8 100644
--- a/pkgs/development/python-modules/notebook/default.nix
+++ b/pkgs/development/python-modules/notebook/default.nix
@@ -67,10 +67,9 @@ buildPythonPackage rec {
     "TestInstallServerExtension"
     "launch_socket"
     "sock_server"
-  ]
-  ++ lib.optional stdenv.isDarwin [
+  ] ++ lib.optional stdenv.isDarwin [
     "test_delete"
-    "test_checkpoints_follow_file" 
+    "test_checkpoints_follow_file"
   ];
 
   # Some of the tests use localhost networking.