Google is investing $22 million into KaiOS, the feature phone operating system that has risen from the ashes of Mozilla’s Firefox OS. While Google rules the smartphone world with Android, KaiOS is slowly emerging as a popular choice for feature phones, particularly in emerging markets. KaiOS started last year as a forked version of Firefox OS, and the operating system ships on some Nokia-branded feature phones like the Nokia 8110. Devices from TCL and Micromax are also powered by KaiOS.

Google’s investment might seem odd given its Android dominance, and its efforts with Android Go, but it’s clearly strategic. “Google and KaiOS have also agreed to work together to make the Google Assistant, Google Maps, YouTube, and Google Search available to KaiOS users,” says KaiOS CEO Sebastien Codeville. KaiOS itself is web-based, designed for developers to use HTML5, Javascript, and CSS for apps. That makes it easy for Google to get these apps running on KaiOS, and strategically ensure feature phones are using Google’s services and not competitors.

More than 40 million KaiOS phones have shipped so far, according to TechCrunch. That’s an impressive number for the feature phone market which is still holding on strong despite smartphones taking over the majority of phone sales.

Google has been pushing to slim down Android to take up less space, reduce pre-installed app space, and to get Android onto devices with 1GB of RAM. That’s good for low-cost smartphone hardware, but Android still takes up around 3GB of storage space and KaiOS devices like the Nokia 8110 banana phone ship with 512MB of RAM and 4GB of storage.

Android may eventually supplant the need for KaiOS, but only if Google can keep pushing to make it more efficient or if the total bill of materials for hardware hits a low enough level where feature phones are no longer required. Either way, Google is covering itself for the future with a clever KaiOS investment.