NEW HAVEN, Connecticut (CNN) — It started as a joke. Cassandra Madison, 32, and Julia Tinetti, 31, began telling people they were sisters not long after they met in 2013 while working at The Russian Lady restaurant in New Haven, Connecticut, but a recent DNA test confirmed that they are actually biological sisters. The two women had a lot in common — they were both adopted from the Dominican Republic as babies, they looked enough alike that customers and coworkers mixed them up all the time and they each had Dominican flag tattoos. The tattoos got them talking and they became fast friends. "We hit it off right away. There was no trying to force a friendship or anything," Madison told CNN. "Our personalities are very similar, so it was very easy for us to just start hanging out."