roommate termination - no rental agreement

[Schwippsy]

What is the name of your state? IL
I have a roommate in my single family home since May this year. We do not have a written rental/roommate agreement. I am selling my house now. How soon can I ask that roommate to leave. He is not very cooperative and does not even want to allow showings in his room when potential buyers show up.
Do I need to give him written notice? He claims he has 90 days, if I gave him notice today. Ineed him to leave as soon as possible.What is the earliest day that I can give him to move out? 2 weeks? 1st of next month? Does he have a right to stay at all since we have no contract?
As always: Thanks so much for your help guys!!
Have a great, tenant trouble free, day
Schwippsy

 

[OHlandlord]

If your roommate has no written contract but has extablished residency there, you need to give 30 days written notice to vacate the premises. If he does not leave, you will have to evict.