diff --git a/pkgs/development/python-modules/nbsphinx/default.nix b/pkgs/development/python-modules/nbsphinx/default.nix
index 22501d467876..cb8470681163 100644
--- a/pkgs/development/python-modules/nbsphinx/default.nix
+++ b/pkgs/development/python-modules/nbsphinx/default.nix
@@ -42,7 +42,7 @@ buildPythonPackage rec {
   # The package has not tests
   doCheck = false;
 
-  JUPYTER_PATH = "${nbconvert}/share/jupyter";
+  env.JUPYTER_PATH = "${nbconvert}/share/jupyter";
 
   pythonImportsCheck = [ "nbsphinx" ];