diff --git a/persistent-data/block.tcc b/persistent-data/block.tcc
index 4867efc..f2f3a7a 100644
--- a/persistent-data/block.tcc
+++ b/persistent-data/block.tcc
@@ -271,7 +271,7 @@ namespace persistent_data {
 		if (bc_.get_nr_locked() > 0)
 			throw std::runtime_error("attempt to lock superblock while other locks are still held");
 
-		block_cache::block &b = bc_.get(location, block_cache::GF_BARRIER, v);
+		block_cache::block &b = bc_.get(location, block_cache::GF_DIRTY | block_cache::GF_BARRIER, v);
 		return write_ref(b, superblock_ref_count_);
 	}