diff --git a/microcloud/test/includes/microcloud.sh b/microcloud/test/includes/microcloud.sh
index 836e9a59f..84827242c 100644
--- a/microcloud/test/includes/microcloud.sh
+++ b/microcloud/test/includes/microcloud.sh
@@ -871,6 +871,7 @@ setup_lxd_project() {
       lxc storage create zpool zfs volume.size=5GiB
     else
       sudo wipefs --all --quiet "${TEST_STORAGE_SOURCE}"
+      sudo blkdiscard "${TEST_STORAGE_SOURCE}" || true
       lxc storage create zpool zfs source="${TEST_STORAGE_SOURCE}"
     fi