diff --git a/MdePkg/Library/BaseLib/BaseLib.inf b/MdePkg/Library/BaseLib/BaseLib.inf
index 49d35c5b4c..60d45a1781 100644
--- a/MdePkg/Library/BaseLib/BaseLib.inf
+++ b/MdePkg/Library/BaseLib/BaseLib.inf
@@ -485,6 +485,7 @@
   X64/WriteMm3.asm | MSFT
   X64/WriteMm2.nasm| MSFT
   X64/WriteMm2.asm | MSFT
+  X64/WriteMm1.nasm| MSFT
   X64/WriteMm1.asm | MSFT
   X64/WriteMm0.asm | MSFT
   X64/ReadMm7.asm | MSFT
@@ -577,6 +578,7 @@
   X64/WriteMm3.asm | INTEL
   X64/WriteMm2.nasm| INTEL
   X64/WriteMm2.asm | INTEL
+  X64/WriteMm1.nasm| INTEL
   X64/WriteMm1.asm | INTEL
   X64/WriteMm0.asm | INTEL
   X64/ReadMm7.asm | INTEL
diff --git a/MdePkg/Library/BaseLib/X64/WriteMm1.nasm b/MdePkg/Library/BaseLib/X64/WriteMm1.nasm
new file mode 100644
index 0000000000..0204a53c44
--- /dev/null
+++ b/MdePkg/Library/BaseLib/X64/WriteMm1.nasm
@@ -0,0 +1,41 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2006, 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
+; http://opensource.org/licenses/bsd-license.php.
+;
+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+;
+; Module Name:
+;
+;   WriteMm1.Asm
+;
+; Abstract:
+;
+;   AsmWriteMm1 function
+;
+; Notes:
+;
+;------------------------------------------------------------------------------
+
+    DEFAULT REL
+    SECTION .text
+
+;------------------------------------------------------------------------------
+; VOID
+; EFIAPI
+; AsmWriteMm1 (
+;   IN UINT64   Value
+;   );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmWriteMm1)
+ASM_PFX(AsmWriteMm1):
+    ;
+    ; 64-bit MASM doesn't support MMX instructions, so use opcode here
+    ;
+    DB      0x48, 0xf, 0x6e, 0xc9
+    ret
+