diff --git a/OvmfPkg/Library/TdxMailboxLib/TdxMailboxLib.inf b/OvmfPkg/Library/TdxMailboxLib/TdxMailboxLib.inf
index 3cf3690a16..e504bda0dd 100644
--- a/OvmfPkg/Library/TdxMailboxLib/TdxMailboxLib.inf
+++ b/OvmfPkg/Library/TdxMailboxLib/TdxMailboxLib.inf
@@ -1,6 +1,6 @@
 #/** @file
 #
-#  TBD
+#  TdxMailbox Library
 #
 #  Copyright (c) 2018, Intel Corporation. All rights reserved.<BR>
 #  Copyright (c) 2008, Apple Inc. All rights reserved.<BR>
@@ -19,12 +19,9 @@
   LIBRARY_CLASS                  = TdxMailboxLib
 
 #
-#  VALID_ARCHITECTURES           = X64 IA32
+#  VALID_ARCHITECTURES           = X64
 #
 
-[Sources.IA32]
-  TdxMailboxNull.c
-
 [Sources.X64]
   TdxMailbox.c
 
diff --git a/OvmfPkg/Library/TdxMailboxLib/TdxMailboxLibNull.inf b/OvmfPkg/Library/TdxMailboxLib/TdxMailboxLibNull.inf
new file mode 100644
index 0000000000..8380d9f4f6
--- /dev/null
+++ b/OvmfPkg/Library/TdxMailboxLib/TdxMailboxLibNull.inf
@@ -0,0 +1,34 @@
+#/** @file
+#
+#  Null instance of TdxMailboxLib
+#
+#  Copyright (c) 2018, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2008, Apple Inc. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+#**/
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = TdxMailboxLibNull
+  FILE_GUID                      = 002a1265-a1a0-47cd-bc69-4342b147f57d
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = TdxMailboxLib
+
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources]
+  TdxMailboxNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib