diff --git a/lib/client.js b/lib/client.js
index c2b28214..49952964 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -7,9 +7,6 @@ const merge = require('merge-descriptors');
 const platform = require('platform');
 const utility = require('utility');
 const urllib = require('urllib');
-const {
-  Base64: { decode: base64ToStr }
-} = require('js-base64');
 const pkg = require('../package.json');
 const bowser = require('bowser');
 const signUtils = require('./common/signUtils');
@@ -381,6 +378,7 @@ proto.requestError = async function requestError(result) {
     err.status = result.status;
     err.code = info.Code;
     err.requestId = info.RequestId;
+    err.ecCode = info.EC;
     err.hostId = info.HostId;
   };
 
@@ -412,7 +410,7 @@ proto.requestError = async function requestError(result) {
         err.status = result.status;
         const ossErr = result.headers['x-oss-err'];
         if (ossErr) {
-          const message = base64ToStr(ossErr);
+          const message = Buffer.from(ossErr, 'base64').toString('utf8');
           await setError(message);
         }
         err.res = result;