Flickr/Kārlis Dambrāns Every year at its Worldwide Developers Conference, Apple reveals the new software features it plans to bring to iPhones, iPads, and MacBooks.

This year's event, which takes place on June 8-12, will likely follow suit, but 9to5Mac's Mark Gurman claims to have already unearthed some details about what to expect from Apple's next big iPhone update.

Gurman has a strong track record when it comes to reporting on upcoming Apple product announcements. Last year, he published screenshots of the new Health app long before iOS 8 was officially unveiled.

Based on his latest reports, here's what we expect to see in iOS 9:

Siri is going to get a redesign . Gurman says the new format will make Siri look more like the colorful version on the Apple Watch.

. Gurman says the new format will make Siri look more like the colorful version on the Apple Watch. Expect new wallpapers and color themes, too . iOS 9 will come with a blue and green color scheme by default, according to the report.

. iOS 9 will come with a blue and green color scheme by default, according to the report. There will be a big focus on security. That's not too surprising, given the iCloud fiasco that happened at the end of 2014. At the same time, Google has been really vocal about the security improvements it's been making to Android as well.

That's not too surprising, given the iCloud fiasco that happened at the end of 2014. At the same time, Google has been really vocal about the security improvements it's been making to Android as well. iOS 9 won't come with many new features, but it will be more stable and smooth. Gurman also reported in February that iOS 9 probably won't be a big visual change. Instead, Apple will emphasize overall improvements to stability and performance. Apple will also try to keep the size of the update manageable so that it's easier for users to actually install the update. When iOS 8 launched in October, some iPhone owners complained they couldn't install the update because it required too much free space.

We expect to know more next month, and the official update will likely roll out in the fall after the next iPhone is announced. In the meantime, Apple is supposedly readying an iOS 8.4 update that will bring a redesigned Music app to the iPhone.