diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
index 21ea2503..a2bcd4fe 100644
--- a/.github/workflows/php.yml
+++ b/.github/workflows/php.yml
@@ -64,6 +64,37 @@ jobs:
           composer global require php-coveralls/php-coveralls
           php-coveralls --coverage_clover=./build/logs/clover.xml -v
 
+  latest_dependency_tests:
+    name: Latest Deps (PHP ${{ matrix.php-versions }})
+    needs: [ linting ]
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        php-versions: [ '8.1', '8.2' ]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+      - name: Set up PHP v${{ matrix.php-versions }}
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-versions }}
+      - name: Install latest supported dependencies
+        run: composer update justinrainbow/json-schema lastguest/murmurhash --with-dependencies
+      - name: Verify latest majors resolved
+        run: |
+          php -r '
+            require "vendor/autoload.php";
+            $jsonSchema = Composer\InstalledVersions::getVersion("justinrainbow/json-schema");
+            $murmur = Composer\InstalledVersions::getVersion("lastguest/murmurhash");
+            echo "json-schema: $jsonSchema\nmurmurhash: $murmur\n";
+            exit((version_compare($jsonSchema, "6.0.0", ">=") && version_compare($murmur, "2.1.0", ">=")) ? 0 : 1);
+          '
+      - name: Run tests
+        run: |
+          mkdir -p ./build/logs
+          ./vendor/bin/phpunit
+
   integration_tests:
     name: Integration Tests
     needs: [ unit_tests ]
diff --git a/composer.json b/composer.json
index 2a28d4cd..7789d037 100644
--- a/composer.json
+++ b/composer.json
@@ -17,8 +17,8 @@
   "require": {
     "php": ">=8.1",
     "guzzlehttp/guzzle": ">=6.2",
-    "justinrainbow/json-schema": "^1.6 || ^2.0 || ^4.0 || ^5.0",
-    "lastguest/murmurhash": "^1.3.0",
+    "justinrainbow/json-schema": "^1.6 || ^2.0 || ^4.0 || ^5.0 || ^6.0",
+    "lastguest/murmurhash": "^1.3.0 || ^2.1",
     "monolog/monolog": ">=1.21"
   },
   "require-dev": {
diff --git a/composer.lock b/composer.lock
index 50ece972..1b2c5812 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": "82b1237943c87584a7fd69a882570e14",
+    "content-hash": "99b7de4d0fca1025e6148d0d08fd66fc",
     "packages": [
         {
             "name": "guzzlehttp/guzzle",
@@ -336,12 +336,12 @@
             "version": "5.2.12",
             "source": {
                 "type": "git",
-                "url": "https://github.com/justinrainbow/json-schema.git",
+                "url": "https://github.com/jsonrainbow/json-schema.git",
                 "reference": "ad87d5a5ca981228e0e205c2bc7dfb8e24559b60"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/justinrainbow/json-schema/zipball/ad87d5a5ca981228e0e205c2bc7dfb8e24559b60",
+                "url": "https://api.github.com/repos/jsonrainbow/json-schema/zipball/ad87d5a5ca981228e0e205c2bc7dfb8e24559b60",
                 "reference": "ad87d5a5ca981228e0e205c2bc7dfb8e24559b60",
                 "shasum": ""
             },
@@ -2808,12 +2808,12 @@
             "version": "3.7.0",
             "source": {
                 "type": "git",
-                "url": "https://github.com/squizlabs/PHP_CodeSniffer.git",
+                "url": "https://github.com/PHPCSStandards/PHP_CodeSniffer.git",
                 "reference": "a2cd51b45bcaef9c1f2a4bda48f2dd2fa2b95563"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/squizlabs/PHP_CodeSniffer/zipball/a2cd51b45bcaef9c1f2a4bda48f2dd2fa2b95563",
+                "url": "https://api.github.com/repos/PHPCSStandards/PHP_CodeSniffer/zipball/a2cd51b45bcaef9c1f2a4bda48f2dd2fa2b95563",
                 "reference": "a2cd51b45bcaef9c1f2a4bda48f2dd2fa2b95563",
                 "shasum": ""
             },
@@ -3785,12 +3785,12 @@
     ],
     "aliases": [],
     "minimum-stability": "stable",
-    "stability-flags": [],
+    "stability-flags": {},
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
         "php": ">=8.1"
     },
-    "platform-dev": [],
-    "plugin-api-version": "2.3.0"
+    "platform-dev": {},
+    "plugin-api-version": "2.9.0"
 }
diff --git a/src/Optimizely/Bucketer.php b/src/Optimizely/Bucketer.php
index 5891649a..908b083c 100644
--- a/src/Optimizely/Bucketer.php
+++ b/src/Optimizely/Bucketer.php
@@ -72,7 +72,11 @@ public function __construct(LoggerInterface $logger)
      */
     private function generateHashCode($bucketingKey)
     {
-        return murmurhash3_int($bucketingKey, Bucketer::$HASH_SEED) & Bucketer::$UNSIGNED_MAX_32_BIT_VALUE;
+        // murmurhash v2 replaced the global function with a static class method
+        $hash = function_exists('murmurhash3_int')
+            ? murmurhash3_int($bucketingKey, Bucketer::$HASH_SEED)
+            : \lastguest\Murmur::hash3_int($bucketingKey, Bucketer::$HASH_SEED);
+        return $hash & Bucketer::$UNSIGNED_MAX_32_BIT_VALUE;
     }
 
     /**
diff --git a/tests/BucketerTest.php b/tests/BucketerTest.php
index 4cbcf8a4..6125d5aa 100644
--- a/tests/BucketerTest.php
+++ b/tests/BucketerTest.php
@@ -88,6 +88,15 @@ public function testGenerateBucketValue()
                 )
             )
         );
+        // Edge cases: empty string and multibyte UTF-8
+        $this->assertSame(
+            3175,
+            $generateBucketValueMethod->invoke(new Bucketer($this->loggerMock), '')
+        );
+        $this->assertSame(
+            8308,
+            $generateBucketValueMethod->invoke(new Bucketer($this->loggerMock), '日本語テスト1886780721')
+        );
     }
 
     public function testBucketValidExperimentNotInGroup()