diff --git a/package.json b/package.json
index 4fd247f..475ea00 100644
--- a/package.json
+++ b/package.json
@@ -26,6 +26,7 @@
     "babel-preset-env": "^1.7.0",
     "babel-preset-es2015": "^6.24.1",
     "base-58": "^0.0.1",
+    "btoa": "^1.2.1",
     "chai": "^4.1.2",
     "crypto-js": "^3.1.9-1",
     "elliptic": "^6.4.0",
diff --git a/src/utils/transactionBuilder.js b/src/utils/transactionBuilder.js
index e698185..4728706 100644
--- a/src/utils/transactionBuilder.js
+++ b/src/utils/transactionBuilder.js
@@ -2,6 +2,8 @@ const decode58Check = require("./crypto").decode58Check;
 const {Block, Transaction, Account} = require("../protocol/core/Tron_pb");
 const google_protobuf_any_pb = require('google-protobuf/google/protobuf/any_pb.js');
 const base64DecodeFromString = require("../lib/code").base64DecodeFromString;
+const btoa = require('btoa');
+
 const {
   TransferContract,
   TransferAssetContract,
diff --git a/yarn.lock b/yarn.lock
index 2dc73cc..765ce8a 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -623,6 +623,9 @@ camelcase@^2.0.1:
 caniuse-lite@^1.0.30000835:
   version "1.0.30000839"
   resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30000839.tgz#41fcc036cf1cb77a0e0be041210f77f1ced44a7b"
+btoa@^1.2.1:
+  version "1.2.1"
+  resolved "https://registry.yarnpkg.com/btoa/-/btoa-1.2.1.tgz#01a9909f8b2c93f6bf680ba26131eb30f7fa3d73"
 
 caseless@~0.12.0:
   version "0.12.0"