diff --git a/validate/data/scenarios/switch_subtitle_track.scenario b/validate/data/scenarios/switch_subtitle_track.scenario
index 83ce3d651d..216e7ce91f 100644
--- a/validate/data/scenarios/switch_subtitle_track.scenario
+++ b/validate/data/scenarios/switch_subtitle_track.scenario
@@ -1,3 +1,3 @@
-description, summary="Change subtitle track at 1 second while playing back", min-subtitle-track=2, duration=5.0
+description, summary="Change subtitle track at 1 second while playing back", min-subtitle-track=2, duration=5.0, need-clock-sync=true
 switch-track, playback-time=1.0, type=text, index=(string)+1
 stop, playback-time=5.0
diff --git a/validate/data/scenarios/switch_subtitle_track_while_paused.scenario b/validate/data/scenarios/switch_subtitle_track_while_paused.scenario
index 15c4ec71be..e90f5795f1 100644
--- a/validate/data/scenarios/switch_subtitle_track_while_paused.scenario
+++ b/validate/data/scenarios/switch_subtitle_track_while_paused.scenario
@@ -1,4 +1,4 @@
-description, summary="Change subtitle track while pipeline is PAUSED", min-subtitle-track=2, duration=5.0, handles-states=true
+description, summary="Change subtitle track while pipeline is PAUSED", min-subtitle-track=2, duration=5.0, handles-states=true, need-clock-sync=true
 pause;
 wait, duration=0.5
 switch-track, type=text, index=(string)+1