diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 3da2d2dfc..cfb69d0ce 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -10,7 +10,7 @@ jobs:
     test:
         strategy:
             matrix:
-                php: [ "8.1", "8.2", "8.3" ]
+                php: [ "8.0", "8.1", "8.2", "8.3", "8.4" ]
                 os: [ ubuntu-latest ]
                 include:
                   - os: windows-latest
@@ -40,7 +40,7 @@ jobs:
             - name: Setup PHP
               uses: shivammathur/setup-php@v2
               with:
-                php-version: "8.1"
+                php-version: "8.0"
             - name: Install Dependencies
               uses: nick-invision/retry@v3
               with:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4e18acfd7..0d3437157 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,18 @@
 
  * [feat]: add support for Firebase v6.0 (#391)
 
+## [1.44.0](https://github.com/googleapis/google-auth-library-php/compare/v1.43.0...v1.44.0) (2024-12-04)
+
+
+### Features
+
+* Add service account impersonation for access tokens ([#586](https://github.com/googleapis/google-auth-library-php/issues/586)) ([ba137b2](https://github.com/googleapis/google-auth-library-php/commit/ba137b2db9ed7ce002cfb4034a1e8d354a85e2fc))
+
+
+### Bug Fixes
+
+* Add support for php 8.4, remove implicit nullable ([#591](https://github.com/googleapis/google-auth-library-php/issues/591)) ([3e1061b](https://github.com/googleapis/google-auth-library-php/commit/3e1061bba19d9340407a9ff70b7b7294c344d17c))
+
 ## [1.43.0](https://github.com/googleapis/google-auth-library-php/compare/v1.42.0...v1.43.0) (2024-11-05)
 
 
diff --git a/VERSION b/VERSION
index b978278f0..372cf402c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.43.0
+1.44.0
diff --git a/composer.json b/composer.json
index 2dfb740d7..33428c5fa 100644
--- a/composer.json
+++ b/composer.json
@@ -9,7 +9,7 @@
     "docs": "https://googleapis.github.io/google-auth-library-php/main/"
   },
   "require": {
-    "php": "^8.1",
+    "php": "^8.0",
     "firebase/php-jwt": "^6.0",
     "guzzlehttp/guzzle": "^7.4.5",
     "guzzlehttp/psr7": "^2.4.5",
diff --git a/src/Credentials/UserRefreshCredentials.php b/src/Credentials/UserRefreshCredentials.php
index 1127ec6be..326f6cd86 100644
--- a/src/Credentials/UserRefreshCredentials.php
+++ b/src/Credentials/UserRefreshCredentials.php
@@ -75,7 +75,7 @@ class UserRefreshCredentials extends CredentialsLoader implements GetQuotaProjec
     public function __construct(
         $scope,
         $jsonKey,
-        string $targetAudience = null
+        ?string $targetAudience = null
     ) {
         if (is_string($jsonKey)) {
             if (!file_exists($jsonKey)) {
diff --git a/tests/HttpHandler/Guzzle7HttpHandlerTest.php b/tests/HttpHandler/Guzzle7HttpHandlerTest.php
index 53147be3a..07ce63005 100644
--- a/tests/HttpHandler/Guzzle7HttpHandlerTest.php
+++ b/tests/HttpHandler/Guzzle7HttpHandlerTest.php
@@ -19,12 +19,10 @@
 
 use Google\Auth\HttpHandler\Guzzle7HttpHandler;
 use Google\Auth\Logging\StdOutLogger;
-use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Promise\Promise;
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\Psr7\Response;
 use Prophecy\Argument;
-use Psr\Log\LoggerInterface;
 
 /**
  * @group http-handler
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 287388b65..e15bbb629 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-error_reporting(E_ALL | E_STRICT);
+error_reporting(E_ALL);
 require dirname(__DIR__) . '/vendor/autoload.php';
 date_default_timezone_set('UTC');