diff --git a/testing/sched/timerjitter/timerjitter.c b/testing/sched/timerjitter/timerjitter.c
index ad956cd4c..3edd10388 100644
--- a/testing/sched/timerjitter/timerjitter.c
+++ b/testing/sched/timerjitter/timerjitter.c
@@ -192,7 +192,8 @@ static FAR void *timerjitter(FAR void *arg)
       diff = calc_diff(&now, &next);
       if (param->print)
         {
-          printf("diff %lu, now %lu.%lu\n", diff, now.tv_sec, now.tv_nsec);
+          printf("diff %"PRId64", now %"PRId64".%09lu\n", diff, now.tv_sec,
+                  now.tv_nsec);
         }
 
       if (diff > param->max)