#angular/cli build issue with default class - angularjs

Question

I am playing around with the #angular/cli tool for projects and building and am having an issue with one of the classes.
I am trying to add a component that is lazyloaded on access of the route:
App route:
const routes: Routes = [
{
path: '',
redirectTo: '/dashboard',
pathMatch: 'full'
},
{
path: 'dashboard',
loadChildren: 'app/dashboard/dashboard.module'
}
];
And a module that loads the components and routes (currently just a simple component that says "Dashboard"):
import { NgModule, ModuleWithProviders } from '#angular/core';
import { Routes, RouterModule } from '#angular/router';
import {
DashboardComponent,
DashboardRoutingModule
} from './index';
#NgModule({
imports: [DashboardRoutingModule],
declarations: [DashboardComponent]
})
export default class DashboardModule { }
When I run ng serve the web page starts as expected and I can develop / see what I am working on.
When I run ng build the project builds ok without any issues.
When I run ng build --prod --aot it returns an errors and a warnings:
WARNING in ./src/$$_gendir/app/dashboard/dashboard.module.ngfactory.ts
31:38-61 "export 'DashboardModule' (imported as 'import1') was not
found in '../../../app/dashboard/dashboard.module'
WARNING in ./src/$$_gendir/app/dashboard/dashboard.module.ngfactory.ts
46:23-46 "export 'DashboardModule' (imported as 'import1') was not
found in '../../../app/dashboard/dashboard.module'
WARNING in ./src/$$_gendir/app/dashboard/dashboard.module.ngfactory.ts
58:91-114 "export 'DashboardModule' (imported as 'import1') was not
found in '../../../app/dashboard/dashboard.module'
ERROR in C:/wamp/www/api/data-portal/src/$$_gendir/app/dashboard/dashboard.module.ngfactory.ts
(1,1): Namespace '"C:/wamp/www/api/data-portal/src/app/dashboard/
dashboard.module"' has no exported member
'DashboardModule'.C:/wamp/www/api/data-portal/src/$$_gendir/app/dashboard/dashboard.module.ngfactory.ts
(1,1): Namespace
'"C:/wamp/www/api/data-portal/src/app/dashboard/dashboard.module"' has
no exported member 'DashboardModule'.
C:/wamp/www/api/data-portal/src/$$_gendir/app/dashboard/dashboard.module.ngfactory.ts
(1,1): Namespace
'"C:/wamp/www/api/data-portal/src/app/dashboard/dashboard.module"' has
no exported member 'DashboardModule'.
If I remove the keyword default from the export of the Dashboard Module, it builds without any issues however then the app doesn't work as it can't find a default, however if I add in the default again it breaks the production build.
Any ideas/thoughts as to what I am doing wrong? I am really confused as ng serve works and ng build works with the default keyword, but ng build --prod --aot does not

Answer 1

I managed to fix this by changing the way I was doing the routing.
Instead of:
{
path: 'dashboard',
loadChildren: 'app/dashboard/dashboard.module'
}
I used:
{
path: 'dashboard',
loadChildren: 'app/dashboard/dashboard.module#DashboardModule'
}
Removing the need for a default in the dashboard module - works perfectly in case anyone has the same issue as me.