Mongoose: Required array field throws error when set as empty array

I have an array field with the following schema on that field:

parents:
    type: 'Array'
    required: true

When I try to create a document with the following data:

data =
    parents: []

Translation.create data, (err, translations) ->
    console.log err, translations

I get the following error:

ValidationError: Path `parents` is required.

If I put a value inside the array it works, like so:

data =
    parents: ['blah']

Similarly, if I remove the required: true from the schema, it also starts working.

Is an empty array not considered satisfactory for "required" validation? I understand it's false in javascript, but there are plenty of cases where empty arrays and objects are intended in Mongo documents.