diff --git a/src/basic/btrfs-util.c b/src/basic/btrfs-util.c
index da4dd2a827..b1519cc4eb 100644
--- a/src/basic/btrfs-util.c
+++ b/src/basic/btrfs-util.c
@@ -1628,7 +1628,7 @@ int btrfs_subvol_snapshot_fd_full(
                 } else if (r < 0)
                         return r;
 
-                r = copy_directory_fd_full(old_fd, new_path, COPY_MERGE|COPY_REFLINK, progress_path, progress_bytes, userdata);
+                r = copy_directory_fd_full(old_fd, new_path, COPY_MERGE|COPY_REFLINK|COPY_SAME_MOUNT, progress_path, progress_bytes, userdata);
                 if (r < 0)
                         goto fallback_fail;