diff --git a/plugins/linux-jack/jack-wrapper.c b/plugins/linux-jack/jack-wrapper.c
index ca7302197..f639b0c8f 100644
--- a/plugins/linux-jack/jack-wrapper.c
+++ b/plugins/linux-jack/jack-wrapper.c
@@ -61,15 +61,11 @@ static enum speaker_layout jack_channels_to_obs_speakers(uint_fast32_t channels)
 int jack_process_callback(jack_nframes_t nframes, void *arg)
 {
 	struct jack_data *data = (struct jack_data *)arg;
-	jack_nframes_t current_frames;
-	jack_time_t current_usecs, next_usecs;
-	float period_usecs;
-
-	uint64_t now = os_gettime_ns();
-
 	if (data == 0)
 		return 0;
 
+	pthread_mutex_lock(&data->jack_mutex);
+
 	struct obs_source_audio out;
 	out.speakers = jack_channels_to_obs_speakers(data->channels);
 	out.samples_per_sec = jack_get_sample_rate(data->jack_client);
@@ -84,19 +80,11 @@ int jack_process_callback(jack_nframes_t nframes, void *arg)
 	}
 
 	out.frames = nframes;
-	if (!jack_get_cycle_times(data->jack_client, &current_frames,
-				  &current_usecs, &next_usecs, &period_usecs)) {
-		out.timestamp = now - (int64_t)(period_usecs * 1000);
-	} else {
-		out.timestamp = now - util_mul_div64(nframes, 1000000000ULL,
-						     data->samples_per_sec);
-		blog(LOG_WARNING,
-		     "jack_get_cycle_times error: guessing timestamp");
-	}
+	out.timestamp = os_gettime_ns() -
+			jack_frames_to_time(data->jack_client, nframes);
 
-	/* FIXME: this function is not realtime-safe, we should do something
-	 * about this */
 	obs_source_output_audio(data->source, &out);
+	pthread_mutex_unlock(&data->jack_mutex);
 	return 0;
 }
 
@@ -127,7 +115,7 @@ int_fast32_t jack_init(struct jack_data *data)
 
 		data->jack_ports[i] = jack_port_register(
 			data->jack_client, port_name, JACK_DEFAULT_AUDIO_TYPE,
-			JackPortIsInput | JackPortIsTerminal, 0);
+			JackPortIsInput, 0);
 		if (data->jack_ports[i] == NULL) {
 			blog(LOG_ERROR,
 			     "jack_port_register Error:"
@@ -163,11 +151,17 @@ void deactivate_jack(struct jack_data *data)
 	pthread_mutex_lock(&data->jack_mutex);
 
 	if (data->jack_client) {
-		jack_client_close(data->jack_client);
 		if (data->jack_ports != NULL) {
+			for (int i = 0; i < data->channels; ++i) {
+				if (data->jack_ports[i] != NULL)
+					jack_port_unregister(
+						data->jack_client,
+						data->jack_ports[i]);
+			}
 			bfree(data->jack_ports);
 			data->jack_ports = NULL;
 		}
+		jack_client_close(data->jack_client);
 		data->jack_client = NULL;
 	}
 	pthread_mutex_unlock(&data->jack_mutex);