diff --git a/MdeModulePkg/Core/PiSmmCore/Notify.c b/MdeModulePkg/Core/PiSmmCore/Notify.c
index eb5059dd70..5ec0aa71a8 100644
--- a/MdeModulePkg/Core/PiSmmCore/Notify.c
+++ b/MdeModulePkg/Core/PiSmmCore/Notify.c
@@ -1,7 +1,7 @@
 /** @file
   Support functions for UEFI protocol notification infrastructure.
 
-  Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2009 - 2013, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials are licensed and made available 
   under the terms and conditions of the BSD License which accompanies this 
   distribution.  The full text of the license may be found at        
@@ -94,6 +94,8 @@ SmmRemoveInterfaceFromProtocol (
   @retval EFI_INVALID_PARAMETER  Invalid parameter
   @retval EFI_SUCCESS            Successfully returned the registration record
                                  that has been added
+  @retval EFI_OUT_OF_RESOURCES   Not enough memory resource to finish the request
+  @retval EFI_NOT_FOUND          If the registration is not found when Function == NULL
 
 **/
 EFI_STATUS
@@ -109,10 +111,40 @@ SmmRegisterProtocolNotify (
   LIST_ENTRY       *Link;
   EFI_STATUS       Status;
 
-  if ((Protocol == NULL) || (Function == NULL) || (Registration == NULL))  {
+  if (Protocol == NULL || Registration == NULL) {
     return EFI_INVALID_PARAMETER;
   }
 
+  if (Function == NULL) {
+  	//
+    // Get the protocol entry per Protocol
+    //
+    ProtEntry = SmmFindProtocolEntry ((EFI_GUID *) Protocol, FALSE);
+    if (ProtEntry != NULL) {
+      ProtNotify = (PROTOCOL_NOTIFY * )*Registration;
+      for (Link = ProtEntry->Notify.ForwardLink;
+           Link != &ProtEntry->Notify;
+           Link = Link->ForwardLink) {
+        //
+        // Compare the notification record 
+        //
+        if (ProtNotify == (CR(Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE))){
+          //
+          // If Registration is an existing registration, then unhook it
+          //
+          ProtNotify->Signature = 0;
+          RemoveEntryList (&ProtNotify->Link);
+          FreePool (ProtNotify);
+          return EFI_SUCCESS;
+        }
+      }
+    }
+    //
+    // If the registration is not found
+    //
+    return EFI_NOT_FOUND;
+  } 
+
   ProtNotify = NULL;
 
   //
diff --git a/MdePkg/Include/Pi/PiSmmCis.h b/MdePkg/Include/Pi/PiSmmCis.h
index 29e5e90675..06d335bfff 100644
--- a/MdePkg/Include/Pi/PiSmmCis.h
+++ b/MdePkg/Include/Pi/PiSmmCis.h
@@ -2,7 +2,7 @@
   Common definitions in the Platform Initialization Specification version 1.2
   VOLUME 4 System Management Mode Core Interface version.
 
-  Copyright (c) 2009 - 2012, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2009 - 2013, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
@@ -106,6 +106,7 @@ EFI_STATUS
   The SmmRegisterProtocolNotify() function creates a registration Function that is to be 
   called whenever a protocol interface is installed for Protocol by 
   SmmInstallProtocolInterface().
+  If Function == NULL and Registration is an existing registration, then the callback is unhooked.
 
   @param[in]  Protocol          The unique ID of the protocol for which the event is to be registered.
   @param[in]  Function          Points to the notification function.
@@ -114,6 +115,7 @@ EFI_STATUS
   @retval EFI_SUCCESS           Successfully returned the registration record that has been added.
   @retval EFI_INVALID_PARAMETER One or more of Protocol, Function and Registration is NULL.
   @retval EFI_OUT_OF_RESOURCES  Not enough memory resource to finish the request.
+  @retval EFI_NOT_FOUND         If the registration is not found when Function == NULL.
 **/
 typedef
 EFI_STATUS