Can't add ViewTab to a proxy view

[papounaise]

It seems that I can't add a ViewTab to a proxy view. Like in :
@register_model_view(MyDeviceProxy, 'frontports')
class MyDeviceProxyFrontPortsView(DeviceComponentsView):
queryset = MyDeviceProxy.objects.all()
child_model = FrontPort
table = DeviceFrontPortTable
filterset = FrontPortFilterSet
template_name = 'dcim/device/frontports.html'
tab = ViewTab(
label=_('Proxy_tab'),
badge=lambda obj: obj.front_port_count,
weight=543,
hide_if_empty=True
)

Any idea about a solution or work around ?