diff --git a/MdePkg/Include/IndustryStandard/Acpi64.h b/MdePkg/Include/IndustryStandard/Acpi64.h
index c905db93fa..3a91302f8c 100644
--- a/MdePkg/Include/IndustryStandard/Acpi64.h
+++ b/MdePkg/Include/IndustryStandard/Acpi64.h
@@ -787,23 +787,26 @@ typedef struct {
   UINT8   Reserved[12];
 } EFI_ACPI_6_4_DEVICE_HANDLE_PCI;
 
+///
+/// Device Handle
+///
+typedef union {
+    EFI_ACPI_6_4_DEVICE_HANDLE_ACPI   Acpi;
+    EFI_ACPI_6_4_DEVICE_HANDLE_PCI    Pci;
+} EFI_ACPI_6_4_DEVICE_HANDLE;
+
 ///
 /// Generic Initiator Affinity Structure
 ///
 typedef struct {
-  UINT8   Type;
-  UINT8   Length;
-  UINT8   Reserved1;
-  UINT8   DeviceHandleType;
-  UINT32  ProximityDomain;
-
-  union {
-    EFI_ACPI_6_4_DEVICE_HANDLE_ACPI   Acpi;
-    EFI_ACPI_6_4_DEVICE_HANDLE_PCI    Pci;
-  } DeviceHandle;
-
-  UINT32  Flags;
-  UINT8   Reserved2[4];
+  UINT8                       Type;
+  UINT8                       Length;
+  UINT8                       Reserved1;
+  UINT8                       DeviceHandleType;
+  UINT32                      ProximityDomain;
+  EFI_ACPI_6_4_DEVICE_HANDLE  DeviceHandle;
+  UINT32                      Flags;
+  UINT8                       Reserved2[4];
 } EFI_ACPI_6_4_GENERIC_INITIATOR_AFFINITY_STRUCTURE;
 
 ///
diff --git a/MdePkg/MdePkg.ci.yaml b/MdePkg/MdePkg.ci.yaml
index 15931eacca..98eaea1c82 100644
--- a/MdePkg/MdePkg.ci.yaml
+++ b/MdePkg/MdePkg.ci.yaml
@@ -3,6 +3,7 @@
 #
 # Copyright (c) Microsoft Corporation
 # Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2021, Arm Limited. All rights reserved.<BR>
 # SPDX-License-Identifier: BSD-2-Clause-Patent
 ##
 {
@@ -19,6 +20,7 @@
         ],
         ## Both file path and directory path are accepted.
         "IgnoreFiles": [
+            "Include/IndustryStandard/Acpi64.h"
         ]
     },
     ## options defined ci/Plugin/CompilerPlugin