diff --git a/hw/xen_disk.c b/hw/xen_disk.c
index 801da58..745127d 100644
--- a/hw/xen_disk.c
+++ b/hw/xen_disk.c
@@ -633,6 +633,8 @@ static int blk_init(struct XenDevice *xendev)
             blkdev->filename  = blkdev->params;
         }
     }
+    if (!strcmp("aio", blkdev->fileproto))
+        blkdev->fileproto = "raw";
     if (blkdev->mode == NULL) {
         blkdev->mode = xenstore_read_be_str(&blkdev->xendev, "mode");
     }