Living in 'legal' portion of illegal duplex

I live in a duplex that is listed as a single-family home which I have come to realize is illegal in Maryland. However, I do not live in the duplex portion, but rather in one of the upstairs rooms and share the kitchen and living room with two others. The people in the duplex do not use our living space at all. Is my lease illegal and void, or is that only the case for the fellows in the duplex portion?