Helmets deforming with facial expression

[shar_N]

As the title says, some helmets in the mod I am playing will deform with the facial expression of the wearer, so I'll see full helmets with squinting eyeslots for example. Is there some way to fix the helmets so that they are rigid the way they appear in Open BRF?

 

[Eärendil Ardamírë]

You need to have an empty base mesh and have the normal helmet (and it's lods) as submesh, so:
helm (empty mesh)
helm.1 (your normal mesh)