diff --git a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
index 401facf475..41001fa2b2 100644
--- a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
+++ b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
@@ -602,7 +602,7 @@ PartitionInstallChildHandle (
   Private->BlockIo.Revision = ParentBlockIo->Revision;
 
   Private->BlockIo.Media    = &Private->Media;
-  CopyMem (Private->BlockIo.Media, ParentBlockIo->Media, SIZE_OF_EFI_BLOCK_IO_MEDIA_REV1);
+  CopyMem (Private->BlockIo.Media, ParentBlockIo->Media, sizeof (EFI_BLOCK_IO_MEDIA));
   Private->Media.LogicalPartition = TRUE;
   Private->Media.LastBlock = DivU64x32 (
                                MultU64x32 (
diff --git a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.h b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.h
index f36c9d411e..d0d0d52a25 100644
--- a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.h
+++ b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.h
@@ -86,9 +86,6 @@ extern EFI_COMPONENT_NAME2_PROTOCOL  gPartitionComponentName2;
                                    (((UINT8 *) a)[3] << 24) )
 
 
-#define SIZE_OF_EFI_BLOCK_IO_MEDIA_REV1  ((UINTN)&((EFI_BLOCK_IO_MEDIA *)0)->LastBlock + sizeof(EFI_LBA))
-#define SIZE_OF_EFI_BLOCK_IO_MEDIA_REV2  sizeof(EFI_BLOCK_IO_MEDIA)
-
 //
 // GPT Partition Entry Status
 //