EnableQueryFilter.ReturnsCollection() throws NullReferenceException for return type void

[eloekset]

I've got an OData API that defines an action like this:

// ExportCustomerLicenseContent
            ActionConfiguration exportCustomerLicenseContent = builder.Action(nameof(CustomerLicenseViewModelsController.ExportCustomerLicenseContent));
            exportCustomerLicenseContent.Parameter<Guid>("CustomerLicenseId");

The controller method returns void. This is intended, and the API works fine. But Swashbuckle.OData expects an action to always have a return type, and fails to generate a SwaggerDocument for my API.