diff --git a/libs/backends/coreaudio/coreaudio_backend.cc b/libs/backends/coreaudio/coreaudio_backend.cc
index 72ec0d277d..04e07000d1 100644
--- a/libs/backends/coreaudio/coreaudio_backend.cc
+++ b/libs/backends/coreaudio/coreaudio_backend.cc
@@ -830,6 +830,11 @@ void *
 CoreAudioBackend::coreaudio_process_thread (void *arg)
 {
 	ThreadData* td = reinterpret_cast<ThreadData*> (arg);
+
+	if (pbd_mach_set_realtime_policy (pthread_self (), period_ns, false)) {
+		PBD::warning << _("AudioEngine: process thread failed to set mach realtime policy.") << endmsg;
+	}
+
 #if MAC_OS_X_VERSION_MAX_ALLOWED >= 110000
 	if (td->_joined_workgroup) {
 		/* have WG */
@@ -871,7 +876,7 @@ int
 CoreAudioBackend::create_process_thread (boost::function<void()> func)
 {
 	pthread_t   thread_id;
-	ThreadData* td = new ThreadData (this, func, PBD_RT_STACKSIZE_PROC);
+	ThreadData* td = new ThreadData (this, func, PBD_RT_STACKSIZE_PROC, 1e9 * _samples_per_period / _samplerate);
 
 #if MAC_OS_X_VERSION_MAX_ALLOWED >= 110000
 	if (_pcmio->workgroup (td->_workgroup)) {
@@ -890,10 +895,6 @@ CoreAudioBackend::create_process_thread (boost::function<void()> func)
 		PBD::warning << _("AudioEngine: process thread failed to acquire realtime permissions.") << endmsg;
 	}
 
-	if (pbd_mach_set_realtime_policy (thread_id, 1e9 * _samples_per_period / _samplerate, false)) {
-		PBD::warning << _("AudioEngine: process thread failed to set mach realtime policy.") << endmsg;
-	}
-
 	_threads.push_back (thread_id);
 	return 0;
 }
diff --git a/libs/backends/coreaudio/coreaudio_backend.h b/libs/backends/coreaudio/coreaudio_backend.h
index 34c17590b8..6ccf1bf3f7 100644
--- a/libs/backends/coreaudio/coreaudio_backend.h
+++ b/libs/backends/coreaudio/coreaudio_backend.h
@@ -388,6 +388,7 @@ class CoreAudioBackend : public AudioBackend, public PortEngineSharedImpl {
 		CoreAudioBackend* engine;
 		boost::function<void ()> f;
 		size_t stacksize;
+		double period_ns;
 
 #if MAC_OS_X_VERSION_MAX_ALLOWED >= 110000
 		bool                      _joined_workgroup;
@@ -395,8 +396,8 @@ class CoreAudioBackend : public AudioBackend, public PortEngineSharedImpl {
 		os_workgroup_join_token_s _join_token;
 #endif
 
-		ThreadData (CoreAudioBackend* e, boost::function<void ()> fp, size_t stacksz)
-			: engine (e) , f (fp) , stacksize (stacksz) {}
+		ThreadData (CoreAudioBackend* e, boost::function<void ()> fp, size_t stacksz, double period)
+			: engine (e) , f (fp) , stacksize (stacksz), period_ns {}
 	};
 
 	/* port engine */