Laravel 5.1 Maintenance Mode Not Working

Hi I am trying to put my Laravel 5.1 app into maintenance mode using the php artisan down command but it is not showing a maintenance page the app continues to function the same.

I can confirm that the down file is being created in storage/app/framework directory and my kernel has the \Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode::class in the global $middleware array.

I have also tried changing the .env APP_ENV and APP_DEBUG values with no success.

If anyone can help me identify why maintenance mode isn't working it would be much appreciated.

via Chebli Mohamed