diff --git a/lib/http/request.js b/lib/http/request.js
index c486f35515..87e21d3de0 100644
--- a/lib/http/request.js
+++ b/lib/http/request.js
@@ -4,7 +4,6 @@ const https  = require('https');
 const dns = require('dns');
 const HttpUtil = require('./http.js');
 const HttpOptions = require('./options.js');
-const fs = require('fs');
 const path = require('path');
 const Auth = require('./auth.js');
 const Formatter = require('./formatter.js');
@@ -418,8 +417,9 @@ class HttpRequest extends EventEmitter {
       bufferArray.push(Buffer.from(delimiter + crlf + header + crlf + crlf));
 
       // set data
+      const {readFileSync} = require('fs');
       if (fieldValue.filePath) {
-        bufferArray.push(fs.readFileSync(fieldValue.filePath));
+        bufferArray.push(readFileSync(fieldValue.filePath));
       } else {
         bufferArray.push(Buffer.from(fieldValue.data));
       }
diff --git a/lib/transport/selenium-webdriver/browserstack/appAutomate.js b/lib/transport/selenium-webdriver/browserstack/appAutomate.js
index 0ec70a9263..727fcdc77a 100644
--- a/lib/transport/selenium-webdriver/browserstack/appAutomate.js
+++ b/lib/transport/selenium-webdriver/browserstack/appAutomate.js
@@ -52,6 +52,7 @@ class AppAutomate extends BrowserStack {
         url: 'https://api-cloud.browserstack.com/app-automate/upload',
         method: 'POST',
         use_ssl: true,
+        port: 443,
         auth: {
           user: this.username,
           pass: this.accessKey
diff --git a/test/src/index/testRequest.js b/test/src/index/testRequest.js
index 0becdd6f0a..d8e8ab1044 100644
--- a/test/src/index/testRequest.js
+++ b/test/src/index/testRequest.js
@@ -415,11 +415,11 @@ describe('test HttpRequest', function() {
   });
 
   it('send POST request with multi-part form data', function(done) {
-    const appPath = path.resolve(__dirname, '../../extra/output/app.apk');
-    const appDir = path.dirname(appPath);
-
-    fs.mkdirSync(appDir, {recursive: true});
-    fs.writeFileSync(appPath, 'app-data');
+    mockery.registerMock('fs', {
+      readFileSync() {
+        return Buffer.from('app-data');
+      }
+    });
 
     const options = {
       method: 'POST',
@@ -428,7 +428,7 @@ describe('test HttpRequest', function() {
       port: 443,
       multiPartFormData: {
         file: {
-          filePath: appPath
+          filePath: 'some/path/app.apk'
         },
         custom_id: {
           data: 'some_app'
@@ -438,8 +438,6 @@ describe('test HttpRequest', function() {
 
     const request = new HttpRequest(options);
     request.on('success', function () {
-      fs.rmSync(appPath);
-
       done();
     }).send();