Meteor Atmosphere packages are not recognized

Importing a Meteor Atmosphere packages like

import {Roles} from "meteor/alanning:roles";

is not recognized by WebStorm and it underlines the name and complains "Module is not installed."

Nevertheless the library is resolved as typing "Roles." brings up suggestions.

Thanks for your help
Markus

P.S. Also to let you know that Meteor runs this without any issues.