Raising rent on long-time inherited tenant.

[Jason Arnett]

I’m under contract for a multi home property, which I am house hacking. I will be inheriting a 20 year tenant, who has been great. According to the current owner, he has never been late on payment, and is a model tenant. The current owner inherited the property from his parents 4 months ago, which is why he has not raised rent. The issue is the current rent is at $350 dollars ( not raised since 2003), which is $400 below local comp. With minor repair and updates (under $2,000), I would expect $875-$925 per month.  I plan on being open and forthcoming about whatever I decide to do on the day of closing. I want to keep him as a tenant, but at the same time I need the extra income from this unit to make the house hack viable. 

I would love to hear any advice, especially if you have experience in situations like these