diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
index 4bcd217917..6227b2428a 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
@@ -23,6 +23,8 @@ SPIN_LOCK                                   *mPFLock = NULL;
 SMM_CPU_SYNC_MODE                           mCpuSmmSyncMode;
 BOOLEAN                                     mMachineCheckSupported = FALSE;
 
+extern UINTN mSmmShadowStackSize;
+
 /**
   Performs an atomic compare exchange operation to get semaphore.
   The compare exchange operation must be performed using
@@ -920,7 +922,7 @@ Gen4GPageTable (
     // Add two more pages for known good stack and stack guard page,
     // then find the lower 2MB aligned address.
     //
-    High2MBoundary = (mSmmStackArrayEnd - mSmmStackSize + EFI_PAGE_SIZE * 2) & ~(SIZE_2MB-1);
+    High2MBoundary = (mSmmStackArrayEnd - mSmmStackSize - mSmmShadowStackSize + EFI_PAGE_SIZE * 2) & ~(SIZE_2MB-1);
     PagesNeeded = ((High2MBoundary - Low2MBoundary) / SIZE_2MB) + 1;
   }
   //
@@ -971,7 +973,7 @@ Gen4GPageTable (
           // Mark the guard page as non-present
           //
           Pte[Index] = PageAddress | mAddressEncMask;
-          GuardPage += mSmmStackSize;
+          GuardPage += (mSmmStackSize + mSmmShadowStackSize);
           if (GuardPage > mSmmStackArrayEnd) {
             GuardPage = 0;
           }
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
index cdc1fcefc5..07e7ea70de 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
@@ -13,6 +13,8 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #define PAGE_TABLE_PAGES            8
 #define ACC_MAX_BIT                 BIT3
 
+extern UINTN mSmmShadowStackSize;
+
 LIST_ENTRY                          mPagePool = INITIALIZE_LIST_HEAD_VARIABLE (mPagePool);
 BOOLEAN                             m1GPageTableSupport = FALSE;
 BOOLEAN                             mCpuSmmRestrictedMemoryAccess;
@@ -1037,7 +1039,7 @@ SmiPFHandler (
       (PFAddress < (mCpuHotPlugData.SmrrBase + mCpuHotPlugData.SmrrSize))) {
     DumpCpuContext (InterruptType, SystemContext);
     CpuIndex = GetCpuIndex ();
-    GuardPageAddress = (mSmmStackArrayBase + EFI_PAGE_SIZE + CpuIndex * mSmmStackSize);
+    GuardPageAddress = (mSmmStackArrayBase + EFI_PAGE_SIZE + CpuIndex * (mSmmStackSize + mSmmShadowStackSize));
     if ((FeaturePcdGet (PcdCpuSmmStackGuard)) &&
         (PFAddress >= GuardPageAddress) &&
         (PFAddress < (GuardPageAddress + EFI_PAGE_SIZE))) {
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c
index 7ef3b1d488..661c1ba294 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c
@@ -93,7 +93,7 @@ InitGdt (
       //
       // Setup top of known good stack as IST1 for each processor.
       //
-      *(UINTN *)(TssBase + TSS_X64_IST1_OFFSET) = (mSmmStackArrayBase + EFI_PAGE_SIZE + Index * mSmmStackSize);
+      *(UINTN *)(TssBase + TSS_X64_IST1_OFFSET) = (mSmmStackArrayBase + EFI_PAGE_SIZE + Index * (mSmmStackSize + mSmmShadowStackSize));
     }
   }