Determine which modules are needed to be included:
On Windows with cygwin:
npm ls --production | grep -i '\-\-' | sed 's/.*-- \(.*\)@.*/- node_modules\\/\1\\/**/g'
You'll get an output like
- node_modules/XXX/**
- node_modules/YYY/**
- node_modules/ZZZ/**
Put it instead of the node_modules includes in package.include
in serverless.yml.