Attention aspiring millennial homebuyers: You may have to deal with that pesky roommate or overbearing landlord for a lot longer than you think.

A survey conducted by rental search site Apartment List found that millennials looking to buy and who want to put down the recommended 20% on their first home may have to save, in some cases, for more than two decades.

The researchers looked at the average self-reported savings rates of millennial respondents and compared it against the median condo sales price in the major metro areas where they live. Here’s a breakdown (courtesy of CNN Money) of how long it’ll take to save for a 20% down payment (and start adulting!) in some of the nation’s biggest cities.

How Long It Takes to Save for a 20% Down Payment in Major U.S. Cities

Miami: 6.3 years
New York City: 8.3 years
Dallas: 9.3 years
Houston: 10.8 years
Washington, D.C.: 11.6 years
Boston: 15.2 years
Denver: 16 years
Los Angeles: 20.7 years
San Jose, California: 23.9 years

The results should come as a wake-up call to homebuyers who may not have a realistic sense of how long it takes to save, and how much putting down 20% really amounts to. Apartment List’s data found that nearly two-thirds of respondents will have to save for more than five years to reach just a 10% down payment.

So if you were hoping to own in just a few years, you may need to rethink your plan a little bit. Renting may prove to be the smarter option in many cases anyways, like if you might move in the next five years, when the housing market is overpriced, if moving would give you a longer commute, or you already have a sweet deal on rent (in which case, lucky you!). But if the American Dream is on your radar, remember to prioritize this major financial goal into your overall budget.