diff --git a/lib/client.js b/lib/client.js
index 4beedfe..8b35a74 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -1,6 +1,6 @@
 /* global URL */
 import pkgJson from '../package.json'
-import { when, isObject, isString, debounce, addUserAgent } from './utils'
+import { when, isObject, isString, debounce, updateUserAgentWithAppId } from './utils'
 import IdleState from './utils/idleState'
 import Tracker from './tracker'
 import NativePromise from 'native-promise-only'
@@ -558,7 +558,7 @@ export default class Client {
       }
 
       const appId = this._metadata && this._metadata.appId
-      options.headers = addUserAgent(options.headers, appId)
+      options.headers = updateUserAgentWithAppId(options.headers, appId)
 
       const doneEventKey = `${requestKey}.done`
       const failEventKey = `${requestKey}.fail`
diff --git a/lib/utils.js b/lib/utils.js
index 5ade59c..2bec38a 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -3,7 +3,7 @@ import pkgJson from '../package.json'
 
 const Promise = window.Promise || NativePromise
 
-export function addUserAgent (headers, appId) {
+export function updateUserAgentWithAppId (headers, appId) {
   const originalUserAgent = headers && headers['User-Agent'] ? headers['User-Agent'] : ''
   const zafSdkUserAgentString = `zendesk_app_framework_sdk/sdk_version:${pkgJson.version}/app_id:${appId}`
   const userAgent = originalUserAgent ? `${originalUserAgent} ${zafSdkUserAgentString}` : zafSdkUserAgentString
diff --git a/package.json b/package.json
index 0d311d9..9a9e2a1 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "zendesk_app_framework_sdk",
-  "version": "2.0.37",
+  "version": "2.0.38",
   "main": "build/zaf_sdk.min.js",
   "description": "The Zendesk App Framework (ZAF) SDK is a JavaScript library that simplifies cross-frame communication between iframed apps and ZAF.",
   "homepage": "http://developer.zendesk.com",
diff --git a/spec/utils_spec.js b/spec/utils_spec.js
index 374caba..033fca1 100644
--- a/spec/utils_spec.js
+++ b/spec/utils_spec.js
@@ -1,6 +1,7 @@
 /* eslint-env mocha */
 /* global expect Promise */
 import * as Utils from '../lib/utils'
+import pkgJson from '../package.json'
 
 describe('Utils', () => {
   let params
@@ -151,4 +152,19 @@ describe('Utils', () => {
       expect(Utils.isObject(['a'])).to.equal(true)
     })
   })
+
+  describe('.updateUserAgentWithAppId', () => {
+    before(() => {
+      // Mock pkgJson
+      global.pkgJson = { version: '1.0.0' }
+    })
+
+    it('should append the app id to the user agent', () => {
+      const headers = { 'User-Agent': 'Mozilla/5.0' }
+      const appId = '1'
+      const updatedHeaders = Utils.updateUserAgentWithAppId(headers, appId)
+      const expectedUserAgent = `Mozilla/5.0 zendesk_app_framework_sdk/sdk_version:${pkgJson.version}/app_id:${appId}`
+      expect(updatedHeaders['User-Agent']).to.equal(expectedUserAgent)
+    })
+  })
 })