When is a window seat not a window seat? When you’re sitting at a window seat and there’s… no window.

There is currently a class action lawsuit against two U.S. airlines for upselling window seats without windows. In a number of cases, they charged travelers up to $169 for a preferred window seat where, due to the seating configuration in that cabin, there is no window.

But these seats are listed as window seats in the seating charts posted on their own websites.

There’s another issue as well. When airlines charge extra for a so-called preferred seat closer to the front of the plane, it turns out to be the dreaded middle seat.

Translation: don’t depend on airline seating charts. Instead, call the airline directly and get them to confirm the exact location of your seat and whether there is, in fact, a window. Then determine if it’s worth it to pay extra.