diff --git a/server/web3service/blockchain.js b/server/web3service/blockchain.js
index 1bb1112..665c19f 100644
--- a/server/web3service/blockchain.js
+++ b/server/web3service/blockchain.js
@@ -6,6 +6,7 @@ const event = require('j7/event');
 const sync = require("j7/sync");
 const log = require("j7/log");
 const contract = require('common/contract');
+const bcconst = require('common/bcconst');
 const metaFactory = require('./metadata/factory');
 
 class BlockChain {