diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec
index 3b1270513e..c49f1ceb03 100644
--- a/MdePkg/MdePkg.dec
+++ b/MdePkg/MdePkg.dec
@@ -611,6 +611,13 @@
   gEfiPersistentVirtualDiskGuid  = { 0x5CEA02C9, 0x4D07, 0x69D3, {0x26, 0x9F ,0x44, 0x96, 0xFB, 0xE0, 0x96, 0xF9 }}
   gEfiPersistentVirtualCdGuid    = { 0x08018188, 0x42CD, 0xBB48, {0x10, 0x0F, 0x53, 0x87, 0xD5, 0x3D, 0xED, 0x3D }}
 
+  #
+  # GUIDs defined in UEFI2.6
+  #
+
+  ## Include/Guid/MemoryAttributesTable.h
+  gEfiMemoryAttributesTableGuid        = { 0xdcfa911d, 0x26eb, 0x469f, {0xa2, 0x20, 0x38, 0xb7, 0xdc, 0x46, 0x12, 0x20}}
+
   #
   # GUID defined in PI1.0
   #