Google has increased its efforts to get cellphone manufacturers and carriers to update to the latest version of Android. That includes speeding up security updates, offering technology workarounds and limiting phone testing requirements. To back up these enticements, Google is also publicly naming the laggards in a ranking intended to shame manufacturers into catching up. At stake are not simply Google’s latest operating system but new offerings such as its Daydream virtual reality system.

According to Bloomberg, fragmentation among manufacturers means that new Google features, including Now on Tap as well as fixes for Stagefright software bugs, “only reach a fraction of Android’s active user base of 1.4 billion.” The result is that Google will have a hard time competing with Apple, which designs and operates both hardware and software.

The difference is stark: whereas 84 percent of Apple’s mobile devices run the latest software, only 7.5 percent of Android devices run Marshmallow, the newest Android OS.

“It’s not an ideal situation,” said Android chief Hiroshi Lockheimer, who describes this as “the weakest link on security on Android.” He reports that Google is making progress on convincing phone manufacturers and carriers to install updates.

Even so, a Dutch consumer group sued Samsung for not updating devices, and the U.S. Federal Communications Commission has sent a letter to phone manufacturers and carriers as well as Google and Apple “asking how they can ensure faster updates.”

Carriers are the slowest to approve updates because testing to ensure they don’t disrupt the network can take months and the company supports so many different Android phones. Sprint executive Ryan Sullivan notes that it has shortened its approval process from 12 weeks to a few weeks.

Since the Stagefright event exposed almost a billion devices to hackers, Google began sending monthly Android security patches to its Nexus devices. LG Electronics and Samsung have committed to monthly updates, but “have struggled to keep to that schedule for all their phones,” and smaller manufacturers haven’t even tried. HTC executive Jason Mackenzie called it “unrealistic” and Motorola is now attempting quarterly updates.

Google, which is attempting to convince carriers to exclude security patches from its full tests, which could save them “several hundred thousand dollars for each model,” also released an early preview of its Android N operating system to give manufacturers more time to adapt.

Mobile security firm Zimperium senior researcher Joshua Drake says Google “has come a long way since Stagefright,” but notes that not all carriers see security as a priority and phone manufacturers are more interested in selling new devices.