diff --git a/Include/Library/OcAppleDiskImageLib.h b/Include/Library/OcAppleDiskImageLib.h
index d4e02dbd..4511bd79 100644
--- a/Include/Library/OcAppleDiskImageLib.h
+++ b/Include/Library/OcAppleDiskImageLib.h
@@ -23,8 +23,8 @@ typedef struct {
     UINT8                           *Buffer;
     UINTN                           Length;
 
-    // Disk image info.
-    APPLE_DISK_IMAGE_TRAILER        Trailer;
+    UINT64                          SectorCount;
+
     UINT32                          BlockCount;
     APPLE_DISK_IMAGE_BLOCK_DATA     **Blocks;
 
diff --git a/Library/OcAppleDiskImageLib/OcAppleDiskImageBlockIo.c b/Library/OcAppleDiskImageLib/OcAppleDiskImageBlockIo.c
index 5761d545..c3468cdd 100644
--- a/Library/OcAppleDiskImageLib/OcAppleDiskImageBlockIo.c
+++ b/Library/OcAppleDiskImageLib/OcAppleDiskImageBlockIo.c
@@ -127,7 +127,7 @@ DiskImageBlockIoReadBlocks (
 
   DiskImageData = OC_APPLE_DISK_IMAGE_MOUNTED_DATA_FROM_THIS (This);
 
-  if (Lba >= DiskImageData->ImageContext->Trailer.SectorCount) {
+  if (Lba >= DiskImageData->ImageContext->SectorCount) {
     return EFI_INVALID_PARAMETER;
   }
 
@@ -284,7 +284,7 @@ OcAppleDiskImageInstallBlockIo (
   DiskImageData->BlockIoMedia.MediaPresent = TRUE;
   DiskImageData->BlockIoMedia.ReadOnly     = TRUE;
   DiskImageData->BlockIoMedia.BlockSize    = APPLE_DISK_IMAGE_SECTOR_SIZE;
-  DiskImageData->BlockIoMedia.LastBlock    = (Context->Trailer.SectorCount - 1);
+  DiskImageData->BlockIoMedia.LastBlock    = (Context->SectorCount - 1);
 
   InternalConstructDmgDevicePath (DiskImageData, RamDmgAddress);
 
diff --git a/Library/OcAppleDiskImageLib/OcAppleDiskImageLib.c b/Library/OcAppleDiskImageLib/OcAppleDiskImageLib.c
index b7b3faf4..86c9f061 100644
--- a/Library/OcAppleDiskImageLib/OcAppleDiskImageLib.c
+++ b/Library/OcAppleDiskImageLib/OcAppleDiskImageLib.c
@@ -207,11 +207,11 @@ OcAppleDiskImageInitializeContext (
     return FALSE;
   }
 
-  DmgContext->Buffer     = BufferBytes;
-  DmgContext->Length     = (TrailerOffset + sizeof (DmgContext->Trailer));
-  DmgContext->BlockCount = DmgBlockCount;
-  DmgContext->Blocks     = DmgBlocks;
-  CopyMem (&DmgContext->Trailer, &Trailer, sizeof (DmgContext->Trailer));
+  DmgContext->Buffer      = BufferBytes;
+  DmgContext->Length      = (TrailerOffset + sizeof (Trailer));
+  DmgContext->BlockCount  = DmgBlockCount;
+  DmgContext->Blocks      = DmgBlocks;
+  DmgContext->SectorCount = Trailer.SectorCount;
 
   *Context = DmgContext;
 
@@ -264,7 +264,7 @@ OcAppleDiskImageRead (
 
   ASSERT (Context != NULL);
   ASSERT (Buffer != NULL);
-  ASSERT (Lba < Context->Trailer.SectorCount);
+  ASSERT (Lba < Context->SectorCount);
 
   LbaCurrent          = Lba;
   RemainingBufferSize = BufferSize;
diff --git a/TestsUser/DiskImage/DiskImage.c b/TestsUser/DiskImage/DiskImage.c
index 2e6d66fe..750f0a22 100644
--- a/TestsUser/DiskImage/DiskImage.c
+++ b/TestsUser/DiskImage/DiskImage.c
@@ -70,7 +70,7 @@ int main (int argc, char *argv[]) {
       continue;
     }
 
-    UncompSize = (DmgContext->Trailer.SectorCount * APPLE_DISK_IMAGE_SECTOR_SIZE);
+    UncompSize = (DmgContext->SectorCount * APPLE_DISK_IMAGE_SECTOR_SIZE);
     UncompDmg  = malloc (UncompSize);
     if (UncompDmg == NULL) {
       printf ("DMG data allocation failed.\n");