diff --git a/ethcore/src/blockchain/blockchain.rs b/ethcore/src/blockchain/blockchain.rs
index 185bcaad3..f412a8240 100644
--- a/ethcore/src/blockchain/blockchain.rs
+++ b/ethcore/src/blockchain/blockchain.rs
@@ -448,7 +448,8 @@ impl BlockChain {
 		let mut write_details = self.block_details.write().unwrap();
 		for (hash, details) in update.block_details.into_iter() {
 			batch.put_extras(&hash, &details);
-			write_details.insert(hash, details);
+			write_details.insert(hash.clone(), details);
+			self.note_used(CacheID::Extras(ExtrasIndex::BlockDetails, hash));
 		}
 
 		let mut write_receipts = self.block_receipts.write().unwrap();
@@ -759,6 +760,14 @@ impl BlockChain {
 
 				// TODO: handle block_hashes properly.
 				block_hashes.clear();
+
+				blocks.shrink_to_fit();
+				block_details.shrink_to_fit();
+ 				block_hashes.shrink_to_fit();
+ 				transaction_addresses.shrink_to_fit();
+ 				block_logs.shrink_to_fit();
+ 				blocks_blooms.shrink_to_fit();
+ 				block_receipts.shrink_to_fit();
 			}
 			if self.cache_size().total() < self.max_cache_size { break; }
 		}