diff --git a/block/src/error.rs b/block/src/error.rs
index ebaa33ec5..afd4b5533 100644
--- a/block/src/error.rs
+++ b/block/src/error.rs
@@ -231,4 +231,56 @@ impl From<io::Error> for BlockError {
     }
 }
 
+/// Temporary scaffolding: classify a `qcow::Error` into the appropriate
+/// `BlockErrorKind`.
+///
+/// This impl exists only to allow an incremental migration of the qcow
+/// parse/construct chain from `qcow::Result` to `BlockResult`. Each
+/// subsequent commit replaces bare `?` sites with explicit
+/// `BlockError::new(kind, e)` calls. Once every site is migrated this
+/// impl will be removed.
+impl From<crate::qcow::Error> for BlockError {
+    fn from(e: crate::qcow::Error) -> Self {
+        use crate::qcow::Error as E;
+        let kind = match &e {
+            // Structural / format violations
+            E::InvalidMagic
+            | E::BackingFileTooLong(_)
+            | E::InvalidBackingFileName(_)
+            | E::InvalidClusterSize
+            | E::InvalidL1TableSize(_)
+            | E::InvalidL1TableOffset
+            | E::InvalidOffset(_)
+            | E::InvalidRefcountTableOffset
+            | E::InvalidRefcountTableSize(_)
+            | E::FileTooBig(_)
+            | E::NoRefcountClusters
+            | E::RefcountTableOffEnd
+            | E::RefcountTableTooLarge
+            | E::TooManyL1Entries(_)
+            | E::TooManyRefcounts(_)
+            | E::SizeTooSmallForNumberOfClusters => BlockErrorKind::InvalidFormat,
+
+            // Unsupported features / versions
+            E::UnsupportedVersion(_)
+            | E::UnsupportedFeature(_)
+            | E::UnsupportedCompressionType
+            | E::UnsupportedBackingFileFormat(_)
+            | E::UnsupportedRefcountOrder
+            | E::BackingFilesDisabled
+            | E::ShrinkNotSupported => BlockErrorKind::UnsupportedFeature,
+
+            // Corrupt image
+            E::CorruptImage => BlockErrorKind::CorruptImage,
+
+            // Nesting depth overflow
+            E::MaxNestingDepthExceeded => BlockErrorKind::Overflow,
+
+            // Everything else is I/O
+            _ => BlockErrorKind::Io,
+        };
+        Self::new(kind, e)
+    }
+}
+
 pub type BlockResult<T> = Result<T, BlockError>;