diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index f3a7fe4cea..2b4d004b96 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -64,6 +64,8 @@
   gEfiStandardErrorDeviceGuid    = { 0xD3B36F2D, 0xD551, 0x11D4, { 0x9A, 0x46, 0x00, 0x90, 0x27, 0x3F, 0xC1, 0x4D }}
   gEfiPeiPeCoffLoaderGuid        = { 0xD8117CFF, 0x94A6, 0x11D4, { 0x9A, 0x3A, 0x00, 0x90, 0x27, 0x3F, 0xC1, 0x4D }}
   gEfiVariableInfoGuid           = { 0xddcf3616, 0x3275, 0x4164, { 0x98, 0xb6, 0xfe, 0x85, 0x70, 0x7f, 0xfe, 0x7d }}
+  gSimpleTextInExNotifyGuid      = { 0x856f2def, 0x4e93, 0x4d6b, { 0x94, 0xce, 0x1c, 0xfe, 0x47, 0x1, 0x3e, 0xa5 }}
+
 
 [Protocols.common]