Samsung has started working on the Android 5.1.1 Lollipop update, the latest version of the Android mobile operating system, for the Galaxy S5, a report said Thursday. While the South Korean technology giant is rumored to bring the Lollipop experience to its 2014 flagship smartphone model, the company’s Galaxy S6 and Galaxy S6 Edge received the update only from a single carrier in the U.S. earlier this week.

According to SamMobile, Samsung is currently working on an important firmware update for the Galaxy S5, which is believed to be the Android 5.1.1 Lollipop. The update, however, will take a few weeks to be released to the public because Samsung has just begun the development process, the report said, citing insider sources.

In addition to the Galaxy S5, Samsung is also said to be testing Android 5.1.1 Lollipop for the Galaxy Note 4. Although there is no information about an exact time frame for the update’s completion, SamMobile said that the new firmware could be rolled out in “a couple of weeks” after the Android 5.1.1 becomes available for the Galaxy S6 and Galaxy S6 Edge across the world.

Another SamMobile report claimed earlier this month that Samsung was testing beta versions of Android 5.1.1 Lollipop for various devices. The report also said that the new firmware could be released for the Galaxy Note 4 by end of July.

On Monday, U.S. carrier T-Mobile began releasing the Android 5.1.1 Lollipop update for Galaxy S6 and Galaxy S6 Edge, bring key bug fixes and new features to the devices. The firmware adds a simplified exposure control system in the camera app, and brings a new wallpaper parallax effect.

The update also brings changes to the user interface, such as the option to remove the S Finder and Quick Connect buttons from the notifications area. The Guest Mode is another significant feature included in the update.

However, it is not confirmed whether the Galaxy S5 will also receive the same features and enhancements.