diff --git a/pkgs/development/python-modules/notebook/default.nix b/pkgs/development/python-modules/notebook/default.nix
index e71a21eeb12b..2d756476dc10 100644
--- a/pkgs/development/python-modules/notebook/default.nix
+++ b/pkgs/development/python-modules/notebook/default.nix
@@ -81,6 +81,7 @@ buildPythonPackage rec {
   ];
 
   env = {
+    CI = 1; # quiet lerna progress bar
     JUPYTER_PLATFORM_DIRS = 1;
   };