diff --git a/car-mirror/src/cache.rs b/car-mirror/src/cache.rs
index 6613a24..ef3b7ac 100644
--- a/car-mirror/src/cache.rs
+++ b/car-mirror/src/cache.rs
@@ -131,7 +131,8 @@ mod quick_cache {
     /// consecutive `has_block` and `get_block` calls.
     #[derive(Debug, Clone)]
     pub struct CacheMissing<B: BlockStore> {
-        inner: B,
+        /// Access to the inner blockstore
+        pub inner: B,
         has_blocks: Arc<sync::Cache<Cid, bool>>,
     }