Prevent installing node modules for package


I’ve noticed that for a large project, Meteor is building the same node modules I have in node_modules of the package into .meteor/local/isopacks/my_module/npm/node_modules. Is there a reason for doing this? The package.js should be all it needs to bundle my package. Is there a way to prevent this? The files are several hundred MBs I don’t need, and they take a long time to download in the event I run meteor reset.