diff --git a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
index 473e0913200c..f10ce7c65bdf 100644
--- a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
+++ b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
@@ -1149,8 +1149,8 @@ PartitionInstallChildHandle (
 
   Private->Signature        = PARTITION_PRIVATE_DATA_SIGNATURE;
 
-  Private->Start            = MultU64x32 (Start, ParentBlockIo->Media->BlockSize);
-  Private->End              = MultU64x32 (End + 1, ParentBlockIo->Media->BlockSize);
+  Private->Start            = MultU64x32 (Start, BlockSize);
+  Private->End              = MultU64x32 (End + 1, BlockSize);
 
   Private->BlockSize        = BlockSize;
   Private->ParentBlockIo    = ParentBlockIo;
@@ -1187,13 +1187,7 @@ PartitionInstallChildHandle (
 
   Private->Media.IoAlign   = 0;
   Private->Media.LogicalPartition = TRUE;
-  Private->Media.LastBlock = DivU64x32 (
-                               MultU64x32 (
-                                 End - Start + 1,
-                                 ParentBlockIo->Media->BlockSize
-                                 ),
-                                BlockSize
-                               ) - 1;
+  Private->Media.LastBlock = End - Start;
 
   Private->Media.BlockSize = (UINT32) BlockSize;