diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec
index b8dd9feb72..70553fe815 100644
--- a/MdePkg/MdePkg.dec
+++ b/MdePkg/MdePkg.dec
@@ -5,7 +5,7 @@
 # It also provides the definitions(including PPIs/PROTOCOLs/GUIDs) of
 # EFI1.10/UEFI2.3.1/PI1.2 and some Industry Standards.
 #
-# Copyright (c) 2007 - 2011, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2007 - 2012, Intel Corporation. All rights reserved.<BR>
 # Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
 #
 # This program and the accompanying materials are licensed and made available under
@@ -216,6 +216,9 @@
   #                  operatation to be replayed during an S3 resume. This
   #                  library class maps directly on top of the Timer class.
   S3StallLib|Include/Library/S3StallLib.h
+  
+  ##  @libraryclass  Defines library APIs used by modules to get/set print error level.
+  DebugPrintErrorLevelLib|Include/Library/DebugPrintErrorLevelLib.h
 
 [LibraryClasses.IA32, LibraryClasses.X64]
   ##  @libraryclass  Abstracts both S/W SMI generation and detection.