Tenants complains about slamming doors

[Christian Bors]

Hello,

I owe a 3 unit building where I live in the basement and rent the other 2 units. I just got a message from the tenant who lives on the top floor complaining about the child in the middle slamming doors. Both tenants have been ideal and tenant did say its a "minor" complaint. However, I don't want this to escalate. I have heard the slamming of the doors, but it doesnt really bother me. The doors the tenant is talking about are the closets doors mostly. What should I do? Are there any products out there that I can install so closets/doors cannot be slammed? Should I just ask the middle floor tenant to not slam the doors?

Thanks.