Boston is notorious for its high real estate prices, making it hard for some to purchase homes in the area. As a result, renting was a plausible solution, until now. Thanks to high credit requirements, Boston is now one of the hardest cities to get approval to rent.

A new report by RentCafe named Boston as the city with the highest average credit score necessary for approval to rent. While 2017’s  average credit score for renters was 650, renters in Boston need an average score of 737 to get a rental approved, according to the report.

San Francisco follows Boston on the list at number two, requiring an average credit score of 724.

Even though San Francisco is the second most expensive U.S. city for renters, with an average rent of $3,440 per month, Boston still requires the higher credit score. Boston is currently the third most expensive U.S. city for renters, with the average rent reaching $3,232 a month.

Renting is the reasonable option for many residents, especially millennials and students, but the prospect of needing a high credit score could further add to the affordable housing crunch in Boston.

In 2017, Boston had the highest concentration of Millennials out of all the U.S. cities at 35 percent, according to the Boston Foundation. The average Millennial credit score is the same as the nation’s average score, 650.