diff --git a/CHANGELOG.md b/CHANGELOG.md
index d06da737..7cb75479 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [4.0.0-rc.0] - 2021-10-13
+
 ### Added
 - You can now use `$smarty->muteUndefinedOrNullWarnings()` to activate convert warnings about undefined or null template vars to notices when running PHP8
 
diff --git a/libs/Smarty.class.php b/libs/Smarty.class.php
index 294c1245..a4840b7e 100644
--- a/libs/Smarty.class.php
+++ b/libs/Smarty.class.php
@@ -98,7 +98,7 @@ class Smarty extends Smarty_Internal_TemplateBase
     /**
      * smarty version
      */
-    const SMARTY_VERSION = '3.1.40';
+    const SMARTY_VERSION = '4.0.0-rc.0';
     /**
      * define variable scopes
      */