diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 502daff..e6bb04b 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -1252,7 +1252,7 @@
 
 	nr_samples = convert_unit(nr_samples, &unit);
 	printed = scnprintf(bf, size,
-			   "Samples: %lu%c of event '%s', Event count (approx.): %lu",
+			   "Samples: %lu%c of event '%s', Event count (approx.): %" PRIu64,
 			   nr_samples, unit, ev_name, nr_events);