diff --git a/components/aes67_ptp/ptp_clock.c b/components/aes67_ptp/ptp_clock.c
index 2b5548b..d8c1372 100644
--- a/components/aes67_ptp/ptp_clock.c
+++ b/components/aes67_ptp/ptp_clock.c
@@ -268,6 +268,9 @@ static void servo(int64_t offset)
         ESP_LOGI(TAG, "clock stepped by %+lld ns (%s), frequency %+.3f ppm", -offset, esp_err_to_name(err),
                  s.freq_ppb / 1000);
         s.stepped = true;
+        s.offset_ns = 0;    // the pre-step offset is history: not for status or the summary
+        s.sum_max_ns = 0;
+        s.sum_start_us = 0;
         s.prev_t2 = 0;      // rate across the step is meaningless
         s.bad = 0;
         set_locked(false);