diff --git a/MdeModulePkg/Bus/Ata/AhciPei/AhciPeiPassThru.c b/MdeModulePkg/Bus/Ata/AhciPei/AhciPeiPassThru.c
index cd55272c96..7bd04661d0 100644
--- a/MdeModulePkg/Bus/Ata/AhciPei/AhciPeiPassThru.c
+++ b/MdeModulePkg/Bus/Ata/AhciPei/AhciPeiPassThru.c
@@ -3,6 +3,7 @@
   mode at PEI phase.
 
   Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+  Copyright (C) 2023 Advanced Micro Devices, Inc. All rights reserved.<BR>
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -92,6 +93,15 @@ AhciPassThruExecute (
 {
   EFI_STATUS  Status;
 
+  if (PortMultiplierPort == 0xFFFF) {
+    //
+    // If there is no port multiplier, PortMultiplierPort will be 0xFFFF
+    // according to UEFI spec. Here, we convert its value to 0 to follow
+    // AHCI spec.
+    //
+    PortMultiplierPort = 0;
+  }
+
   switch (Packet->Protocol) {
     case EFI_ATA_PASS_THRU_PROTOCOL_ATA_NON_DATA:
       Status = AhciNonDataTransfer (