diff --git a/libs/backends/coreaudio/coreaudio_backend.cc b/libs/backends/coreaudio/coreaudio_backend.cc
index 04e07000d1..da74dcc2ef 100644
--- a/libs/backends/coreaudio/coreaudio_backend.cc
+++ b/libs/backends/coreaudio/coreaudio_backend.cc
@@ -831,7 +831,7 @@ CoreAudioBackend::coreaudio_process_thread (void *arg)
 {
 	ThreadData* td = reinterpret_cast<ThreadData*> (arg);
 
-	if (pbd_mach_set_realtime_policy (pthread_self (), period_ns, false)) {
+	if (pbd_mach_set_realtime_policy (pthread_self (), td->period_ns, false)) {
 		PBD::warning << _("AudioEngine: process thread failed to set mach realtime policy.") << endmsg;
 	}