diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8085d16a..a7160ff4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # CHANGELOG
 
-## v6.0.0 (2022-12-15)
+## v6.0.0-rc1 (2022-12-15)
 
 - PHP 7.3 is no longer supported
 - Added a new `EasyPostClient` object which encapsulates the API key. All functions are called against this client allowing for thread-safety (eg: `$client->shipment->create()`)
diff --git a/composer.json b/composer.json
index fa41b276..d53a2262 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
   "name": "easypost/easypost-php",
   "description": "EasyPost Shipping API Client Library for PHP",
-  "version": "6.0.0",
+  "version": "6.0.0-rc1",
   "keywords": [
     "shipping",
     "api",
diff --git a/composer.lock b/composer.lock
index 26015e83..6247c605 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "e0507a264b1d0515529a54e637a8d548",
+    "content-hash": "ed44804dbf8fb20c26da057f20fbfc73",
     "packages": [
         {
             "name": "guzzlehttp/guzzle",
diff --git a/lib/EasyPost/Constant/Constants.php b/lib/EasyPost/Constant/Constants.php
index 3382a07b..fddbec64 100644
--- a/lib/EasyPost/Constant/Constants.php
+++ b/lib/EasyPost/Constant/Constants.php
@@ -11,7 +11,7 @@ abstract class Constants
     const BETA_API_VERSION = 'beta';
 
     // Library constants
-    const LIBRARY_VERSION = '6.0.0';
+    const LIBRARY_VERSION = '6.0.0-rc1';
     const SUPPORT_EMAIL = 'support@easypost.com';
 
     // Validation