diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2565d61..6b94e4d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [1.16.2] - 2023-02-02
+
+### Changed
+- PHP 8.1 compatibility fix
+
 ## [1.16.1] - 2023-01-23
 
 ### Changed
diff --git a/plugin.php b/plugin.php
index 59caaad..3a49969 100644
--- a/plugin.php
+++ b/plugin.php
@@ -3,7 +3,7 @@
  * Plugin Name: RediPress
  * Plugin URI:  https://github.com/devgeniem/redipress
  * Description: A WordPress plugin that provides a blazing fast search engine and WP Query performance enhancements.
- * Version:     1.16.1
+ * Version:     1.16.2
  * Author:      Geniem
  * Author URI:  http://www.geniem.fi/
  * License:     GPL3
diff --git a/src/Utility.php b/src/Utility.php
index f7779d3..d76c91b 100644
--- a/src/Utility.php
+++ b/src/Utility.php
@@ -28,7 +28,7 @@ public static function format( array $source ) : array {
         $source = self::recursive_to_string( $source );
 
         // Remove possible first integer
-        if ( filter_var( $source[0], FILTER_VALIDATE_INT ) ) {
+        if ( isset( $source[0] ) && filter_var( $source[0], FILTER_VALIDATE_INT ) ) {
             unset( $source[0] );
         }