diff --git a/tools/perf/python/twatch.py b/tools/perf/python/twatch.py
index df638c438a9..b11cca58423 100755
--- a/tools/perf/python/twatch.py
+++ b/tools/perf/python/twatch.py
@@ -19,7 +19,7 @@ def main():
 	cpus = perf.cpu_map()
 	threads = perf.thread_map()
 	evsel = perf.evsel(task = 1, comm = 1, mmap = 0,
-			   wakeup_events = 1, sample_period = 1,
+			   wakeup_events = 1, watermark = 1,
 			   sample_id_all = 1,
 			   sample_type = perf.SAMPLE_PERIOD | perf.SAMPLE_TID | perf.SAMPLE_CPU | perf.SAMPLE_TID)
 	evsel.open(cpus = cpus, threads = threads);