diff --git a/backend/converter.py b/backend/converter.py
index 788f300..508b8d2 100644
--- a/backend/converter.py
+++ b/backend/converter.py
@@ -22,7 +22,7 @@ STAGING_IN = STAGING_ROOT / "in"
 
 logger = logging.getLogger("backend.converter")
 
-DISK_EXTENSIONS = {".vmdk", ".qcow2", ".qcow", ".img", ".raw", ".vhd", ".vhdx"}
+DISK_EXTENSIONS = {".vmdk", ".qcow2", ".qcow", ".img", ".raw", ".vhd", ".vhdx", ".vdi"}
 
 ARCHIVE_EXTENSIONS = {".7z", ".zip", ".rar", ".tar.gz", ".tgz", ".tar", ".gz", ".bz2", ".xz", ".ova"}