Minimum age to get in to Circa Nightclub, Toronto?

I am 20 years old and I've been to Circa myself, many times, and never been refused admission with ID. My Question is: I'm about to buy the tickets for New Years countdown party,but the flyer says "21+ ID", unlike MOST other events that are "19+ ID". It looks like some nights they raise the minimum age to 21+. Does anyone know if they ENFORCE this? I don't wanna pay for the tickets and then end up bounced at the door...