diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index 87b960e941ba..b6f66a9886ce 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c
@@ -1654,6 +1654,7 @@ ptp_ocp_signal_set(struct ptp_ocp *bp, int gen, struct ptp_ocp_signal *s)
 	if (!s->start) {
 		/* roundup() does not work on 32-bit systems */
 		s->start = DIV64_U64_ROUND_UP(start_ns, s->period);
+		s->start *= s->period;
 		s->start = ktime_add(s->start, s->phase);
 	}