diff --git a/StandaloneMmPkg/StandaloneMmPkg.dec b/StandaloneMmPkg/StandaloneMmPkg.dec
index 82cb62568b..36de8d561b 100644
--- a/StandaloneMmPkg/StandaloneMmPkg.dec
+++ b/StandaloneMmPkg/StandaloneMmPkg.dec
@@ -2,7 +2,7 @@
 # This package is a platform package that provide platform module/library
 # required by Standalone MM platform.
 #
-# Copyright (c) 2016-2018, ARM Ltd. All rights reserved.<BR>
+# Copyright (c) 2016-2021, Arm Ltd. All rights reserved.<BR>
 #
 # SPDX-License-Identifier: BSD-2-Clause-Patent
 #
@@ -19,6 +19,24 @@
 
 [LibraryClasses]
 
+  ##  @libraryclass  Defines a set of helper methods.
+  FvLib|Include/Library/FvLib.h
+
+  ##  @libraryclass  Defines a set of interfaces for the MM core entrypoint.
+  StandaloneMmCoreEntryPoint|Include/Library/StandaloneMmCoreEntryPoint.h
+
+  ##  @libraryclass  Defines a set of interfaces for the MM driver entrypoint.
+  StandaloneMmDriverEntryPoint|Include/Library/StandaloneMmDriverEntryPoint.h
+
+  ##  @libraryclass  Defines a set of interfaces that provides services for
+  ##                 MM Memory Operation.
+  MemLib|Include/Library/StandaloneMmMemLib.h
+
+[LibraryClasses.AArch64]
+  ##  @libraryclass  Defines a set of interfaces for the MM core entrypoint for
+  ##                 AArch64.
+  StandaloneMmCoreEntryPoint|Include/Library/AArch64/StandaloneMmCoreEntryPoint.h
+
 [Guids]
   gStandaloneMmPkgTokenSpaceGuid           = { 0x18fe7632, 0xf5c8, 0x4e63, { 0x8d, 0xe8, 0x17, 0xa5, 0x5c, 0x59, 0x13, 0xbd }}
   gMpInformationHobGuid                    = { 0xba33f15d, 0x4000, 0x45c1, { 0x8e, 0x88, 0xf9, 0x16, 0x92, 0xd4, 0x57, 0xe3 }}