Eloquent withtrashed() for soft deletes on eager loading query - Laravel 5.1

I'm trying to use withTrashed() with eager loading. I've created a new _withtrashed function in my model, but the query comes back with a NULL for my client

Client model:

// Client
public function client()
{
    return $this->belongsTo('App\Client');
}

// Client (withtrashed for soft deletes)
public function client_withtrashed()
{
    return $this->belongsTo('App\Client')->withTrashed();
}

Order controller

/**
 * Show order.
 */
public function show($id)
{
    $order = Order::with('client_withtrashed')    ---> it works normally with: Order::with('client') , except I don't get the soft deleted rows
            ->where('id', '=', $id)
            ->firstOrFail();

dd($order); displays an empty client

#relations: array:1 [
   "client_withtrashed" => null 

Any ideas? I decided on the solution above because I couldn't get withTrashed() to work with my eager query $order = Order::with('client_withtrashed')->withTrashed()

via Chebli Mohamed