diff --git a/block/src/fixed_vhd_async.rs b/block/src/fixed_vhd_async.rs
index 141435420..5f4c6d842 100644
--- a/block/src/fixed_vhd_async.rs
+++ b/block/src/fixed_vhd_async.rs
@@ -13,8 +13,9 @@ use crate::async_io::{
 use crate::error::{BlockError, BlockResult, ErrorOp};
 use crate::fixed_vhd::FixedVhd;
 use crate::raw_async::RawFileAsync;
-use crate::{BatchRequest, BlockBackend};
+use crate::{BatchRequest, BlockBackend, disk_file};
 
+#[derive(Debug)]
 pub struct FixedVhdDiskAsync(FixedVhd);
 
 impl FixedVhdDiskAsync {
@@ -50,6 +51,12 @@ impl DiskFile for FixedVhdDiskAsync {
     }
 }
 
+impl disk_file::DiskSize for FixedVhdDiskAsync {
+    fn logical_size(&self) -> BlockResult<u64> {
+        Ok(self.0.logical_size().unwrap())
+    }
+}
+
 pub struct FixedVhdAsync {
     raw_file_async: RawFileAsync,
     size: u64,