diff --git a/src/clock.c b/src/clock.c
index eac425151..3d96c31d0 100644
--- a/src/clock.c
+++ b/src/clock.c
@@ -284,6 +284,7 @@ void clock_init_thread_date(void)
 	now.tv_sec = old_now >> 32;
 	now.tv_usec = (uint)old_now;
 	th_ctx->idle_pct = 100;
+	th_ctx->prev_cpu_time  = now_cpu_time();
 	clock_update_date(0, 1);
 }