diff --git a/CHANGELOG.md b/CHANGELOG.md
index b127df3..a96c76e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## v4.2.2
+* `url-helper.ts` now leverages well-known environment variables by @jww3 in https://github.com/actions/checkout/pull/1941
+* Expand unit test coverage for `isGhes` by @jww3 in https://github.com/actions/checkout/pull/1946
+
 ## v4.2.1
 * Check out other refs/* by commit if provided, fall back to ref by @orhantoy in https://github.com/actions/checkout/pull/1924
 
diff --git a/__test__/url-helper.test.ts b/__test__/url-helper.test.ts
index 27f6606..57cb28f 100644
--- a/__test__/url-helper.test.ts
+++ b/__test__/url-helper.test.ts
@@ -24,13 +24,50 @@ describe('getServerUrl tests', () => {
 })
 
 describe('isGhes tests', () => {
+  const pristineEnv = process.env
+
+  beforeEach(() => {
+    jest.resetModules()
+    process.env = {...pristineEnv}
+  })
+
+  afterAll(() => {
+    process.env = pristineEnv
+  })
+
   it('basics', async () => {
+    delete process.env['GITHUB_SERVER_URL']
     expect(urlHelper.isGhes()).toBeFalsy()
     expect(urlHelper.isGhes('https://github.com')).toBeFalsy()
     expect(urlHelper.isGhes('https://contoso.ghe.com')).toBeFalsy()
     expect(urlHelper.isGhes('https://test.github.localhost')).toBeFalsy()
     expect(urlHelper.isGhes('https://src.onpremise.fabrikam.com')).toBeTruthy()
   })
+
+  it('returns false when the GITHUB_SERVER_URL environment variable is not defined', async () => {
+    delete process.env['GITHUB_SERVER_URL']
+    expect(urlHelper.isGhes()).toBeFalsy()
+  })
+
+  it('returns false when the GITHUB_SERVER_URL environment variable is set to github.com', async () => {
+    process.env['GITHUB_SERVER_URL'] = 'https://github.com'
+    expect(urlHelper.isGhes()).toBeFalsy()
+  })
+
+  it('returns false when the GITHUB_SERVER_URL environment variable is set to a GitHub Enterprise Cloud-style URL', async () => {
+    process.env['GITHUB_SERVER_URL'] = 'https://contoso.ghe.com'
+    expect(urlHelper.isGhes()).toBeFalsy()
+  })
+
+  it('returns false when the GITHUB_SERVER_URL environment variable has a .localhost suffix', async () => {
+    process.env['GITHUB_SERVER_URL'] = 'https://mock-github.localhost'
+    expect(urlHelper.isGhes()).toBeFalsy()
+  })
+
+  it('returns true when the GITHUB_SERVER_URL environment variable is set to some other URL', async () => {
+    process.env['GITHUB_SERVER_URL'] = 'https://src.onpremise.fabrikam.com'
+    expect(urlHelper.isGhes()).toBeTruthy()
+  })
 })
 
 describe('getServerApiUrl tests', () => {
diff --git a/package-lock.json b/package-lock.json
index 281b2ea..25753a2 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "checkout",
-  "version": "4.2.1",
+  "version": "4.2.2",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "checkout",
-      "version": "4.2.1",
+      "version": "4.2.2",
       "license": "MIT",
       "dependencies": {
         "@actions/core": "^1.10.1",
diff --git a/package.json b/package.json
index e145004..5661d70 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "checkout",
-  "version": "4.2.1",
+  "version": "4.2.2",
   "description": "checkout action",
   "main": "lib/main.js",
   "scripts": {