diff --git a/MdePkg/Include/Ppi/CpuIo.h b/MdePkg/Include/Ppi/CpuIo.h
index d34c38d5e0..1daf8257a3 100644
--- a/MdePkg/Include/Ppi/CpuIo.h
+++ b/MdePkg/Include/Ppi/CpuIo.h
@@ -465,6 +465,6 @@ struct _EFI_PEI_CPU_IO_PPI {
   EFI_PEI_CPU_IO_PPI_MEM_WRITE64  MemWrite64;
 };
 
-extern EFI_GUID gEfiPeiCpuIoPpiInServiceTableGuid;
+extern EFI_GUID gEfiPeiCpuIoPpiInstalledGuid;
 
 #endif
diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec
index e744722cdc..f65a5a34fe 100644
--- a/MdePkg/MdePkg.dec
+++ b/MdePkg/MdePkg.dec
@@ -172,7 +172,7 @@
   gEfiPeiStatusCodePpiGuid = { 0x229832d3, 0x7a30, 0x4b36, {0xb8, 0x27, 0xf4, 0xc, 0xb7, 0xd4, 0x54, 0x36 } }
   gEfiPeiSecurity2PpiGuid = { 0xdcd0be23, 0x9586, 0x40f4, { 0xb6, 0x43, 0x6, 0x52, 0x2c, 0xed, 0x4e, 0xde } }
   gEfiTemporaryRamSupportPpiGuid = { 0xdbe23aa9, 0xa345, 0x4b97, {0x85, 0xb6, 0xb2, 0x26, 0xf1, 0x61, 0x73, 0x89} }
-  gEfiPeiCpuIoPpiGuid = { 0xe6af1f7b, 0xfc3f, 0x46da, {0xa8, 0x28, 0xa3, 0xb4, 0x57, 0xa4, 0x42, 0x82 } }
+  gEfiPeiCpuIoPpiInstalledGuid = { 0xe6af1f7b, 0xfc3f, 0x46da, {0xa8, 0x28, 0xa3, 0xb4, 0x57, 0xa4, 0x42, 0x82 } }
   gEfiPciCfg2PpiGuid = { 0x57a449a, 0x1fdc, 0x4c06, { 0xbf, 0xc9, 0xf5, 0x3f, 0x6a, 0x99, 0xbb, 0x92 } }
   gEfiPeiStallPpiGuid = { 0x1f4c6f90, 0xb06b, 0x48d8, {0xa2, 0x01, 0xba, 0xe5, 0xf1, 0xcd, 0x7d, 0x56 } }
   gEfiPeiReadOnlyVariable2PpiGuid = { 0x2ab86ef5, 0xecb5, 0x4134, { 0xb5, 0x56, 0x38, 0x54, 0xca, 0x1f, 0xe1, 0xb4 } }
@@ -183,7 +183,6 @@
   gEfiPeiLoadFilePpiGuid = { 0xb9e0abfe, 0x5979, 0x4914, { 0x97, 0x7f, 0x6d, 0xee, 0x78, 0xc2, 0x78, 0xa6 } }
   gEfiPeiDecompressPpiGuid = { 0x1a36e4e7, 0xfab6, 0x476a, { 0x8e, 0x75, 0x69, 0x5a, 0x5, 0x76, 0xfd, 0xd7 } }
   gPcdPpiGuid = { 0x6e81c58, 0x4ad7, 0x44bc, { 0x83, 0x90, 0xf1, 0x2, 0x65, 0xf7, 0x24, 0x80 } }
-  gEfiPeiCpuIoPpiInServiceTableGuid = { 0xe6af1f7b, 0xfc3f, 0x46da, {0xa8, 0x28, 0xa3, 0xb4, 0x57, 0xa4, 0x42, 0x82} }
   gEfiEndOfPeiSignalPpiGuid = { 0x605EA650, 0xC65C, 0x42e1, { 0xBA, 0x80, 0x91, 0xA5, 0x2A, 0xB6, 0x18, 0xC6 }}