The Xperia Z4 may be a bit of a letdown, but Sony can still turn things around with a few flagship variants. Recent leaks suggest an Xperia Z4 Ultra and Z4 Compact will arrive as soon as this summer.

The new devices bubbled up recently when a pair new Sony smartphones were spotted in the Indonesia’s POSTEL regulatory database. The leak listed two handsets with model numbers similar to last year’s Xperia Z3 Compact and the original Z Ultra, suggesting new Z4 variants are inbound.

On Wednesday, the Xperia Z4 Compact surfaced again, this time in a catalog from Japanese carrier NTT DoCoMo. The smaller flagship phone will apparently launch sometime this summer, though there’s no mention of the larger Ultra model. Still, the flagship phablet may not be far behind.

Rumor has it Sony is already working on a more powerful handset. One report claimed it could be called the Z3+, but the Z4 Ultra makes a lot more sense. Either way, it’s possible the device could arrive as soon as September at the IFA expo in Berlin.

We’re expecting the Xperia Z4 Compact to offer a 4.7-inch 1080p display, a Snapdragon 810 processor, 3GB of RAM, 32GB of storage, a 20.7-megapixel rear camera and a 5-megapixel front-facing shooter. Meanwhile, the Z4 Ultra could pack a 6.44-inch or 5.9-inch Quad HD display, depending on the rumor, a bigger battery, a 16-megapixel camera, 4GB of RAM and a stylus. None of these specs are confirmed though, and it’s likely Sony is still weighing its options ahead of a potential launch later this year.