diff --git a/block/vhdx.c b/block/vhdx.c
index 050f071..158edab 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -985,7 +985,7 @@
 
     sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits;
 
-    sinfo->file_offset = s->bat[sinfo->bat_idx] >> VHDX_BAT_FILE_OFF_BITS;
+    sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK;
 
     sinfo->block_offset = block_offset << s->logical_sector_size_bits;
 
@@ -999,7 +999,6 @@
      * in the block, and add in the payload data block offset
      * in the file, in bytes, to get the final read address */
 
-    sinfo->file_offset <<= 20;  /* now in bytes, rather than 1MB units */
     sinfo->file_offset += sinfo->block_offset;
 }
 
@@ -1098,8 +1097,7 @@
 {
     /* The BAT entry is a uint64, with 44 bits for the file offset in units of
      * 1MB, and 3 bits for the block state. */
-    s->bat[sinfo->bat_idx]  = ((sinfo->file_offset>>20) <<
-                               VHDX_BAT_FILE_OFF_BITS);
+    s->bat[sinfo->bat_idx]  = sinfo->file_offset;
 
     s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK;
 
diff --git a/block/vhdx.h b/block/vhdx.h
index f331548..d3598e0 100644
--- a/block/vhdx.h
+++ b/block/vhdx.h
@@ -229,7 +229,6 @@
 /* upper 44 bits are the file offset in 1MB units lower 3 bits are the state
    other bits are reserved */
 #define VHDX_BAT_STATE_BIT_MASK 0x07
-#define VHDX_BAT_FILE_OFF_BITS (64 - 44)
 #define VHDX_BAT_FILE_OFF_MASK  0xFFFFFFFFFFF00000 /* upper 44 bits */
 typedef uint64_t VHDXBatEntry;