diff --git a/persistent-data/block.tcc b/persistent-data/block.tcc
index 1ffb0c7..e1ced4a 100644
--- a/persistent-data/block.tcc
+++ b/persistent-data/block.tcc
@@ -344,7 +344,7 @@ block_manager<BlockSize>::block_manager(std::string const &path,
 					unsigned max_concurrent_blocks,
 					typename block_io<BlockSize>::mode mode)
 	: io_(new block_io<BlockSize>(path, nr_blocks, mode)),
-	  cache_(max(64u, max_concurrent_blocks)),
+	  cache_(max(1024u, max_concurrent_blocks)),
 	  tracker_(0, nr_blocks)
 {
 }