Apple’s Worldwide Developer Conference, which opened June 5, could sound the death knell for nearly 10,000 mobile travel apps.

Apple has given strong hints that the conference, which marks the debut of iOS 11, will also mark the end of the road for apps that have not upgraded to use the 64-bit processors that have been available since September 2013.

The travel apps are a drop in the bucket of apps that are likely to be given the boot from the App Store: In all, 187,000 apps will be incompatible with future iOS versions, according to SensorTower, a marketing intelligence company that covers mobile app sellers.

Most notably, they won’t work with iOS 11, which was rolled out to developers with the onset of the conference and will go into public beta in late June. It will be universally available in the fall.

The top categories of apps destined for extinction are games (38,619) and educational apps (19,765).

Big name-brand travel companies – airlines, large hotels and chains and car rental firms – seem to have heard Apple’s many warning messages indicating that old, outdated apps will not be welcome in the App Store.

But some popular destination apps developed by small companies are disappearing.

Last fall, Apple made good on a promise to purge outdated and abandoned apps.

While it normally weeds out 10,000 to 15,000 apps over the course of a month, it deleted about 47,300 in October.

On the day before its developer conference opened, Apple removed 32-bit apps from search results for a brief period. It apparently was a test.

Earlier this year, a warning appeared on iOS 10.3 devices when users launched a 32-bit app: It stated that unless the developer updated the app, it would not be compatible with future iOS versions.