Since its debut, the Apple Watch has sported the same relative form factor and design. But that could change this fall, a new report suggests.

The so-called Apple Watch Series 4 could adopt an all-new design, larger battery capacity and a display that’s 15 percent larger than current models, well-connected KGI Securities analyst Ming-Chi Kuo wrote in an investor’s note distributed this week.

Kuo didn’t expand on what the refresh could look like beyond saying the S4 would have a “more trendy form factor design.” It’s also unclear if the Apple Watch Series 4’s chassis will be larger to accommodate the larger display, or whether the device would simply adopt slimmer bezels or a curved-screen design.

But since the Apple Watch’s design has remained unchanged for the better part of three years, a refresh would make sense.

In addition to a form factor revamp, Apple will likely introduce a new CPU and improve graphics performance for the 2018 Apple Watch, though Kuo was vague about its internal specifications. Presumably, the larger battery capacity would be a result of larger physical size or more efficient battery tech.

Kuo added that the S4 would come equipped with a new suite of sensors that would expand its health monitoring capabilities.

We’re not sure what this “enhanced” monitoring would entail, but rumors suggest that Apple is developing a non-invasive blood glucose monitoring system, as well as a sensor for continuous ECG analysis.

The analyst predicts that Apple will sell somewhere between 22 and 24 million units throughout 2018, which would represent a 30 percent year-over-year increase in shipments. That’ll be largely driven by the Apple Watch S4’s new design and features, as well as a drop in price on older Apple wearables.

In the long-term, Kuo forecasts that Apple Watch sales would reach about 50 million units a year. If it does reach that level, the revenue the Cupertino tech giant draws in for its flagship wearable could be on-par with iPad or Mac sales.

KGI Securities expects the Apple Watch S4 to launch in the third quarter of this year. It’ll likely be unveiled at Apple’s annual September keynote, alongside new iPhones and iPad Pro devices.