Run npm install from parent folder on windows

I have following project structure:

 -app
  -client
  -server

I need to run npm install from server folder (i have build script) So i running

npm --prefix "../client" install

But instead of going to parent folder, npm creating folder with .. name and client inside. And trying to run npm install there. And installation fails because package.json is not there.

On linux its working fine.

How can i define relative path from parent folder ?

via Vovan