A union representing doormen in New York City and a building owners’ association continued contract negotiations into late Monday.

The two sides are trying to avert a strike that could inconvenience tenants at the city’s fanciest apartment buildings.

The sides are fighting over wages and benefits, including health care, sick days and overtime rules.

The union represents 30,000 apartment workers – including doormen, concierges, porters and superintendents.

The current contract expires at 12:01 a.m. April 21. Negotiations began March 9.