Sony says its PlayStation 5 can load virtual worlds far faster than ever before, thanks to one of the fastest solid-state drives ever made — but it’s also not a particularly big drive. Sony has confirmed to The Verge that you won’t be able to expand that blazing-fast SSD storage on day one.

While the PS5 features a dedicated internal slot that can theoretically fit standard stick-shaped M.2 SSDs and an easy way to access it, the slot will apparently be disabled out of the box. “[T]his is reserved for a future update,” Sony tells The Verge.

If you’ve been paying close attention to PS5 news, this won’t be a big surprise. PlayStation hardware architect Mark Cerny spent several minutes talking up the SSD storage expansion feature as part of his technical preview back in March, but he also said at the time that support was likely to be “a bit past” launch.

“It’d be great if that happened by launch, but it’s likely to be a bit past it, so please hold off on getting that M.2 drive until you hear from us,” Cerny said.

What’s the holdup? As Cerny explained, not all M.2 SSDs are fast enough to keep up with the PS5, thin enough to fit into the SSD bay, or compatible with Sony’s I/O controller — and Sony promised to do compatibility testing late this year to make sure.

At the very least, Cerny suggested, off-the-shelf SSDs would need to deliver more than 5.5GB/sec of bandwidth over a PCIe Gen4 connection, and not have a giant heatsink so large that they won’t fit into the PS5’s drive bay.

The Verge