diff --git a/MdeModulePkg/Bus/Scsi/ScsiDiskDxe/ScsiDisk.c b/MdeModulePkg/Bus/Scsi/ScsiDiskDxe/ScsiDisk.c
index eb50889943..88bce3f70c 100644
--- a/MdeModulePkg/Bus/Scsi/ScsiDiskDxe/ScsiDisk.c
+++ b/MdeModulePkg/Bus/Scsi/ScsiDiskDxe/ScsiDisk.c
@@ -256,6 +256,7 @@ ScsiDiskDriverBindingStart (
 
   case EFI_SCSI_TYPE_CDROM:
     ScsiDiskDevice->BlkIo.Media->BlockSize = 0x800;
+    ScsiDiskDevice->BlkIo.Media->ReadOnly  = TRUE;
     MustReadCapacity = FALSE;
     break;
   }