--- a/testing/talos/talos/test.py
+++ b/testing/talos/talos/test.py
@@ -552,17 +552,18 @@ class basic_compositor_video(PageloaderT
     timeout = 10000
     sps_profile_interval = 1
     sps_profile_entries = 2000000
     preferences = {'full-screen-api.allow-trusted-requests-only': False,
                    'layers.acceleration.force-enabled': False,
                    'layers.acceleration.disabled': True,
                    'layout.frame_rate': 0,
                    'docshell.event_starvation_delay_hint': 1,
-                   'full-screen-api.warning.timeout': 500}
+                   'full-screen-api.warning.timeout': 500,
+                   'media.ruin-av-sync.enabled': True}
     filters = filter.ignore_first.prepare(1) + filter.median.prepare()
     unit = 'ms/frame'
     lower_is_better = True
 
 
 @register_test()
 class tcanvasmark(PageloaderTest):
     """