diff --git a/premix/dumper.nim b/premix/dumper.nim
index 41ae4e71a..8c2563ea6 100644
--- a/premix/dumper.nim
+++ b/premix/dumper.nim
@@ -17,6 +17,7 @@ proc dumpDebug(chainDB: BaseChainDB, blockNumber: Uint256) =
     captureChainDB = newBaseChainDB(captureTrieDB, false)
 
   let
+    transaction = memoryDB.beginTransaction()
     parentNumber = blockNumber - 1
     parent = captureChainDB.getBlockHeader(parentNumber)
     header = captureChainDB.getBlockHeader(blockNumber)
@@ -26,6 +27,9 @@ proc dumpDebug(chainDB: BaseChainDB, blockNumber: Uint256) =
 
   captureChainDB.setHead(parent, true)
   let validationResult = processBlock(captureChainDB, parent, header, body, vmState)
+
+  # success or not dispose it
+  transaction.dispose()
   dumpDebuggingMetaData(captureChainDB, header, body, vmState, false)
 
 proc main() =