Yosemite on unsupported Mac Mini

I have an ancient Mac Mini running Yosemite and OS X Server “headless”—after a bit of finagling—and all is well and good for the most part. However, my system log is getting spammed with the following every 10 seconds or so:

Jul 20 12:27:32 foo.bar watchdogd[80881]: [watchdog_daemon] @( wd_watchdog_open) - IOIteratorNext failed (kr=0)
Jul 20 12:27:32 foo.bar watchdogd[80881]: [watchdog_daemon] @( wd_daemon_init) - could not initialize the hardware watchdog
Jul 20 12:27:32 foo.bar watchdogd[80881]: [watchdog_daemon] @( main) - cannot initialize the watchdog service
Jul 20 12:27:32 foo com.apple.xpc.launchd[1] (com.apple.watchdogd): Service only ran for 0 seconds. Pushing respawn out by 10 seconds.

Google is not turning up anything useful. It looks tricky to disable, and I’m not convinced that’s the best (or only) course of action. Any suggestions, lazyweb?