diff --git a/merkle-tree/src/db/common/adminDbConnection.js b/merkle-tree/src/db/common/adminDbConnection.js
index 01cd3a4..c1de11e 100644
--- a/merkle-tree/src/db/common/adminDbConnection.js
+++ b/merkle-tree/src/db/common/adminDbConnection.js
@@ -10,8 +10,13 @@ else url = `mongodb://${host}:${port}`;
 dbConnections.admin = mongoose.createConnection(`${url}/${databaseName}`, {
   useNewUrlParser: true,
   useCreateIndex: true,
+  authSource: "admin",
+  user: "admin",
+  pass: "admin",
+  useUnifiedTopology: true,
+  useFindAndModify: false 
 });
 
 const adminDbConnection = dbConnections.admin;
 
-export default adminDbConnection;
+export default adminDbConnection;
\ No newline at end of file
diff --git a/merkle-tree/src/utils-web3.js b/merkle-tree/src/utils-web3.js
index 54472c9..f499f9b 100644
--- a/merkle-tree/src/utils-web3.js
+++ b/merkle-tree/src/utils-web3.js
@@ -206,10 +206,8 @@ async function subscribeToEvent(
     type: 'event',
     signature: '0x881cc8af0159324ccea314ad98a0cf26fe0e460c2afa693c92f591613d4de7b2' }
   */
-  const eventJsonInterface = web3.utils._.find(
-    contractInstance._jsonInterface, // eslint-disable-line no-underscore-dangle
-    o => o.name === eventName && o.type === 'event',
-  );
+
+  const eventJsonInterface = contractInstance._jsonInterface.find(o => o.name === eventName && o.type === 'event');
 
   logger.silly(`eventJsonInterface: ${JSON.stringify(eventJsonInterface, null, 2)}`);