diff --git a/block/src/qcow/qcow_raw_file.rs b/block/src/qcow/qcow_raw_file.rs
index ceebfd1a9..d3a9ad7ab 100644
--- a/block/src/qcow/qcow_raw_file.rs
+++ b/block/src/qcow/qcow_raw_file.rs
@@ -80,6 +80,7 @@ impl QcowRawFile {
             };
             buffer.write_u64::<BigEndian>(val)?;
         }
+        buffer.flush()?;
         Ok(())
     }