diff --git a/drivers/ieee802154/ieee802154_nrf5.c b/drivers/ieee802154/ieee802154_nrf5.c
index 6c2bd653b8..f8b15b9b86 100644
--- a/drivers/ieee802154/ieee802154_nrf5.c
+++ b/drivers/ieee802154/ieee802154_nrf5.c
@@ -527,7 +527,12 @@ static bool nrf5_tx_at(struct nrf5_802154_data *nrf5_radio, struct net_pkt *pkt,
 		.extra_cca_attempts = max_extra_cca_attempts,
 #endif
 	};
-	uint64_t tx_at = net_ptp_time_to_ns(net_pkt_timestamp(pkt)) / NSEC_PER_USEC;
+
+	/* The timestamp points to the start of PHR but `nrf_802154_transmit_raw_at`
+	 * expects a timestamp pointing to start of SHR.
+	 */
+	uint64_t tx_at = nrf_802154_timestamp_phr_to_shr_convert(
+		net_ptp_time_to_ns(net_pkt_timestamp(pkt)) / NSEC_PER_USEC);
 
 	return nrf_802154_transmit_raw_at(payload, tx_at, &metadata);
 }
diff --git a/include/zephyr/net/ieee802154_radio.h b/include/zephyr/net/ieee802154_radio.h
index cc8ac4d20b..ae175ac8e8 100644
--- a/include/zephyr/net/ieee802154_radio.h
+++ b/include/zephyr/net/ieee802154_radio.h
@@ -52,7 +52,7 @@ extern "C" {
  */
 #define IEEE802154_PHY_SYMBOLS_PER_SECOND(symbol_period) (USEC_PER_SEC / symbol_period)
 
-/* see section 19.2.4 */
+/* in bytes, see section 19.2.4 */
 #define IEEE802154_PHY_SUN_FSK_PHR_LEN 2
 
 /* Default PHY PIB attribute aTurnaroundTime, in PHY symbols, see section 11.3, table 11-1. */
diff --git a/modules/openthread/platform/radio.c b/modules/openthread/platform/radio.c
index c96c3c31ad..cc1ef4e835 100644
--- a/modules/openthread/platform/radio.c
+++ b/modules/openthread/platform/radio.c
@@ -58,6 +58,8 @@ LOG_MODULE_REGISTER(LOG_MODULE_NAME, CONFIG_OPENTHREAD_L2_LOG_LEVEL);
 
 #define CHANNEL_COUNT OT_RADIO_2P4GHZ_OQPSK_CHANNEL_MAX - OT_RADIO_2P4GHZ_OQPSK_CHANNEL_MIN + 1
 
+#define PHY_SHR_DURATION 160 /* duration of SHR in us */
+
 enum pending_events {
 	PENDING_EVENT_FRAME_TO_SEND, /* There is a tx frame to send  */
 	PENDING_EVENT_FRAME_RECEIVED, /* Radio has received new frame */
@@ -395,7 +397,7 @@ void transmit_message(struct k_work *tx_job)
 	    (sTransmitFrame.mInfo.mTxInfo.mTxDelay != 0)) {
 #if defined(CONFIG_NET_PKT_TXTIME)
 		uint32_t tx_at = sTransmitFrame.mInfo.mTxInfo.mTxDelayBaseTime +
-				 sTransmitFrame.mInfo.mTxInfo.mTxDelay;
+				 sTransmitFrame.mInfo.mTxInfo.mTxDelay + PHY_SHR_DURATION;
 		struct net_ptp_time timestamp =
 			ns_to_net_ptp_time(convert_32bit_us_wrapped_to_64bit_ns(tx_at));
 		net_pkt_set_timestamp(tx_pkt, &timestamp);
diff --git a/tests/subsys/openthread/radio_test.c b/tests/subsys/openthread/radio_test.c
index 87a7013a0d..fb6c875503 100644
--- a/tests/subsys/openthread/radio_test.c
+++ b/tests/subsys/openthread/radio_test.c
@@ -30,6 +30,8 @@ DEFINE_FFF_GLOBALS;
 #define FRAME_TYPE_MASK 0x07
 #define FRAME_TYPE_ACK	0x02
 
+#define PHY_SHR_DURATION 160
+
 K_SEM_DEFINE(ot_sem, 0, 1);
 
 /**
@@ -293,10 +295,10 @@ ZTEST(openthread_radio, test_tx_test)
 		get_time_mock_fake.return_val = (int64_t)UINT32_MAX * NSEC_PER_USEC + 1000;
 		frm->mInfo.mTxInfo.mTxDelayBaseTime = 3U;
 		frm->mInfo.mTxInfo.mTxDelay = 5U;
-		expected_target_time =
-			get_time_mock_fake.return_val +
-			(frm->mInfo.mTxInfo.mTxDelayBaseTime + frm->mInfo.mTxInfo.mTxDelay) *
-				NSEC_PER_USEC;
+		expected_target_time = get_time_mock_fake.return_val +
+				       (frm->mInfo.mTxInfo.mTxDelayBaseTime +
+					frm->mInfo.mTxInfo.mTxDelay + PHY_SHR_DURATION) *
+					       NSEC_PER_USEC;
 	}
 
 	/* ACKed frame */