Doorbell Pro not waterproof

I have a concern about my doorbell pro - I have just installed at side door and it is not protected by a overhang - I was told today that the doorbell pro is not waterproof - which I am afraid will prove problematic.  Any suggestions?  This is an expensive doorbell - I purchased one already for my front door which does have a overhang -- liked it so well that i purchased another one for the side door assuming that a doorbell would automatically perform in all weather elements.