diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4f54fdaf7c..f4abc5f613 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -45,6 +45,10 @@
 
 ### 4.2.0
 [Full Changelog](https://github.com/parse-community/parse-server/compare/4.1.0...4.2.0)
+
+__BREAKING CHANGES:__
+- CHANGE: The Sign-In with Apple authentication adapter parameter `client_id` has been changed to `clientId`. If using the Apple authentication adapter, this change requires to update the Parse Server configuration accordingly. See [#6523](https://github.com/parse-community/parse-server/pull/6523) for details.
+___
 - UPGRADE: Parse JS SDK to 2.12.0 [#6548](https://github.com/parse-community/parse-server/pull/6548)
 - NEW: Support Group aggregation on multiple columns for Postgres [#6483](https://github.com/parse-community/parse-server/pull/6483). Thanks to [Siddharth Ramesh](https://github.com/srameshr).
 - FIX: Improve test reliability by instructing Travis to only install one version of Postgres [#6490](https://github.com/parse-community/parse-server/pull/6490). Thanks to
diff --git a/spec/AuthenticationAdapters.spec.js b/spec/AuthenticationAdapters.spec.js
index 2465ab1181..5edb702ba4 100644
--- a/spec/AuthenticationAdapters.spec.js
+++ b/spec/AuthenticationAdapters.spec.js
@@ -1165,7 +1165,7 @@ describe('apple signin auth adapter', () => {
 
   it('(using client id as array) should throw error with missing id_token', async () => {
     try {
-      await apple.validateAuthData({}, { client_id: ['secret'] });
+      await apple.validateAuthData({}, { clientId: ['secret'] });
       fail();
     } catch (e) {
       expect(e.message).toBe('id token is invalid for this user.');
@@ -1249,7 +1249,7 @@ describe('apple signin auth adapter', () => {
     try {
       await apple.validateAuthData(
         { id: 'the_user_id', token: 'the_token' },
-        { client_id: ['secret'] }
+        { clientId: ['secret'] }
       );
       fail();
     } catch (e) {
@@ -1411,7 +1411,7 @@ describe('apple signin auth adapter', () => {
 
   // TODO: figure out a way to generate our own apple signed tokens, perhaps with a parse apple account
   // and a private key
-  xit('(using client id as string) should throw error with invalid jwt client_id', async () => {
+  xit('(using client id as string) should throw error with invalid jwt clientId', async () => {
     try {
       await apple.validateAuthData(
         { id: 'INSERT ID HERE', token: 'INSERT APPLE TOKEN HERE' },
@@ -1425,7 +1425,7 @@ describe('apple signin auth adapter', () => {
 
   // TODO: figure out a way to generate our own apple signed tokens, perhaps with a parse apple account
   // and a private key
-  xit('(using client id as array) should throw error with invalid jwt client_id', async () => {
+  xit('(using client id as array) should throw error with invalid jwt clientId', async () => {
     try {
       await apple.validateAuthData(
         { id: 'INSERT ID HERE', token: 'INSERT APPLE TOKEN HERE' },