diff --git a/blocktx/peer_handler.go b/blocktx/peer_handler.go
index e3a912527..b3f9766ea 100644
--- a/blocktx/peer_handler.go
+++ b/blocktx/peer_handler.go
@@ -495,8 +495,8 @@ func (bs *PeerHandler) markTransactionsAsMined(blockId uint64, merkleTree []*cha
 				return fmt.Errorf("failed to insert block transactions at block height %d: %v", blockHeight, err)
 			}
 			// free up memory
-			txs = txs[:0]
-			merklePaths = merklePaths[:0]
+			txs = make([]*blocktx_api.TransactionAndSource, 0, bs.transactionStorageBatchSize)
+			merklePaths = make([]string, 0, bs.transactionStorageBatchSize)
 
 			// print stats, call gc and chec the result
 			bs.printMemStats()