diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 93dab6423a04..9aafa332828f 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -2770,7 +2770,7 @@ static size_t trace__fprintf_tp_fields(struct trace *trace, struct evsel *evsel,
 		printed += syscall_arg_fmt__scnprintf_val(arg, bf + printed, size - printed, &syscall_arg, val);
 	}
 
-	return printed + fprintf(trace->output, "%s", bf);
+	return printed + fprintf(trace->output, "%.*s", (int)printed, bf);
 }
 
 static int trace__event_handler(struct trace *trace, struct evsel *evsel,