Can BI 4.1 promote to BI 4.0 environment?

Hi,

I've been encouraged to upgrade my BI environment from 4.0 SP3 to 4.1.

Usually, (for other software), I would upgrade my non-production environment first, then upgrade my production environment at a later date.

If I upgrade my nonprod environment to 4.0, will I still have the power to promote to my 4.1 environment?