diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 945df14..7e5cc62 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: [7.4, 8.0]
+        php: [7.4, 8.0, 8.1, 8.2, 8.3]
 
     env:
       ESB_CONSOLE_PORT: 8080
@@ -68,7 +68,7 @@ jobs:
         run: composer install --no-interaction
 
       - name: Composer Require Checker
-        run: composer-require-checker
+        run: composer-require-checker --config-file=composer-require-checker.json
 
       - name: Run Easy Coding Standard
         run: vendor/bin/ecs check
@@ -84,7 +84,10 @@ jobs:
         run: sudo bash ./upload-textfiles "/var/log/elasticsearch/*.log"
 
       - name: Install roave/backward-compatibility-check.
-        run: composer require -W --dev roave/backward-compatibility-check --no-plugins
+        run: |
+          # Install BC check tool in separate directory to avoid dependency conflicts 
+          mkdir -p test-tools/bc-check
+          composer require --working-dir="test-tools/bc-check" roave/backward-compatibility-check --no-plugins
 
       - name: Run roave/backward-compatibility-check.
-        run: vendor/bin/roave-backward-compatibility-check --format=github-actions
+        run: test-tools/bc-check/vendor/bin/roave-backward-compatibility-check --format=github-actions
diff --git a/Dockerfile b/Dockerfile
index c3ab0fa..1183000 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-ARG PHP_VERSION=8.0
+ARG PHP_VERSION=8.3
 
 FROM php:${PHP_VERSION}-cli-alpine
 
diff --git a/README.md b/README.md
index 4f92fcb..9425545 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ Webgriffe ESB is designed to use a single binary which is used as the main entry
 
 Requirements
 ------------
-* PHP 7.2, 7.3 or 7.4
+* PHP 7.4, 8.0, 8.1, 8.2, 8.3
 * Beanstalk
 * Elasticsearch 7.*
 
diff --git a/composer-require-checker.json b/composer-require-checker.json
index 6d5bb51..7dfd157 100644
--- a/composer-require-checker.json
+++ b/composer-require-checker.json
@@ -1,3 +1,9 @@
 {
-  "scan-files" : ["bin/esb"]
+  "scan-files" : ["bin/esb"],
+  "symbol-whitelist": [
+    "null", "true", "false", "static", "self", "parent",
+    "array", "string", "int", "float", "bool", "iterable", "callable", "void", "object", "mixed", "never",
+
+    "mb_convert_encoding"
+  ]
 }
diff --git a/composer.json b/composer.json
index 7e7334e..4a10cf7 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,7 @@
         }
     ],
     "require": {
-        "php": "~7.4.0|~8.0.0",
+        "php": "~7.4.0|~8.0.0|~8.1.0|~8.2.0|~8.3.0",
         "ext-pcntl": "*",
         "ext-json": "*",
         "symfony/dependency-injection": "^4.3",
@@ -33,11 +33,14 @@
         "symfony/property-info": "^4.3",
         "doctrine/annotations": "^1.8",
         "ramsey/uuid": "^3.8",
-        "webgriffe/amp-elasticsearch": "^2.0",
+        "webgriffe/amp-elasticsearch": "dev-php-8.3-support#6b26a581fc99c6aba5b06fc2eabfe2dec98578c9 as 2.1",
         "pagerfanta/pagerfanta": "^2.4",
         "symfony/deprecation-contracts": "^2.1",
         "amphp/http-server-form-parser": "^1.1"
     },
+    "suggest": {
+        "ext-mbstring": "*"
+    },
     "autoload": {
         "psr-4": {
             "Webgriffe\\Esb\\": ["src/"]
@@ -65,5 +68,11 @@
         "phpstan": "vendor/bin/phpstan analyse --no-progress -l max -c phpstan.neon src/",
         "phpunit": "vendor/bin/phpunit",
         "tests": ["@ecs", "@phpstan", "@phpunit"]
+    },
+    "repositories": {
+        "amp-elasticsearch-from-src": {
+            "type": "vcs",
+            "url": "git@github.com:youwe-petervanderwal/amp-elasticsearch.git"
+        }
     }
 }
diff --git a/src/NonUtf8Cleaner.php b/src/NonUtf8Cleaner.php
index 88a9b1b..b1e296d 100644
--- a/src/NonUtf8Cleaner.php
+++ b/src/NonUtf8Cleaner.php
@@ -4,8 +4,6 @@
 
 namespace Webgriffe\Esb;
 
-use Monolog\Utils;
-
 /**
  * @internal
  */
@@ -17,13 +15,34 @@ class NonUtf8Cleaner
      */
     public static function clean(array $data): array
     {
-        array_walk_recursive($data, [Utils::class, 'detectAndCleanUtf8']);
+        array_walk_recursive($data, [__CLASS__, 'cleanString']);
         return $data;
     }
 
     public static function cleanString(string $data): string
     {
-        Utils::detectAndCleanUtf8($data);
-        return $data;
+        // Implementation borrowed from Monolog\Utils::detectAndCleanUtf8() which is no longer a public method as of version 2
+
+        if (preg_match('//u', $data)) {
+            return $data;
+        }
+
+        $data = preg_replace_callback(
+            '/[\x80-\xFF]+/',
+            function ($m) {
+                return function_exists('mb_convert_encoding') ? mb_convert_encoding($m[0], 'UTF-8', 'ISO-8859-1') : utf8_encode($m[0]);
+            },
+            $data
+        );
+
+        if (!is_string($data)) {
+            throw new \RuntimeException('Failed to preg_replace_callback: ' . preg_last_error());
+        }
+
+        return str_replace(
+            ['¤', '¦', '¨', '´', '¸', '¼', '½', '¾'],
+            ['€', 'Š', 'š', 'Ž', 'ž', 'Œ', 'œ', 'Ÿ'],
+            $data
+        );
     }
 }