diff --git a/lxd/storage/backend_lxd.go b/lxd/storage/backend_lxd.go
index c95c49601378..0dee387d1c54 100644
--- a/lxd/storage/backend_lxd.go
+++ b/lxd/storage/backend_lxd.go
@@ -1858,7 +1858,7 @@ func (b *lxdBackend) imageConversionFiller(imgPath string, imgFormat string, op
 			_ = from.Close()
 		}
 
-		to, err := os.OpenFile(diskPath, unix.O_DIRECT|unix.O_RDONLY, 0)
+		to, err := os.OpenFile(diskPath, unix.O_DIRECT|unix.O_WRONLY, 0)
 		if err == nil {
 			cmd = append(cmd, "-t", "none")
 			_ = to.Close()