diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index a72c0ead..63e39381 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -14,12 +14,17 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        php: [8.2, 8.3, 8.4]
-        laravel: [11, 12]
+        php: [ 8.2, 8.3, 8.4, 8.5 ]
+        laravel: [ 11, 12, 13 ]
+        exclude:
+          - laravel: 13
+            php: 8.2
+          - laravel: 11
+            php: 8.5
 
     steps:
       - name: Checkout Code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
@@ -34,7 +39,7 @@ jobs:
         run: composer require "laravel/framework:^${{ matrix.laravel }}" --no-update
 
       - name: Install dependencies
-        uses: nick-fields/retry@v3
+        uses: nick-fields/retry@v4
         with:
           timeout_minutes: 5
           max_attempts: 5
diff --git a/composer.json b/composer.json
index e17755fd..dd721ce4 100644
--- a/composer.json
+++ b/composer.json
@@ -25,7 +25,7 @@
         "php": "^8.2",
         "ext-json": "*",
         "laravel-json-api/neomerx-json-api": "^5.0.3",
-        "laravel/framework": "^11.0|^12.0",
+        "laravel/framework": "^11.0|^12.0|^13.0",
         "nyholm/psr7": "^1.8",
         "ramsey/uuid": "^4.0",
         "symfony/psr-http-message-bridge": "^7.0"
@@ -33,11 +33,11 @@
     "require-dev": {
         "ext-sqlite3": "*",
         "guzzlehttp/guzzle": "^7.8",
-        "laravel-json-api/testing": "^3.1",
+        "laravel-json-api/testing": "^3.2",
         "laravel/legacy-factories": "^1.4.0",
         "laravel/ui": "^4.6",
         "mockery/mockery": "^1.6",
-        "orchestra/testbench": "^9.0|^10.0",
+        "orchestra/testbench": "^9.0|^10.0|^11.0",
         "phpunit/phpunit": "^10.5|^11.0"
     },
     "suggest": {
diff --git a/phpunit.xml b/phpunit.xml
index f4ddf567..ff42d8e3 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -11,29 +11,29 @@
          cacheDirectory=".phpunit.cache"
          backupStaticProperties="false"
          failOnWarning="true"
-         failOnDeprecation="true"
+         failOnDeprecation="false"
          failOnNotice="true"
 >
-  <coverage/>
-  <testsuites>
-    <testsuite name="Unit">
-      <directory suffix="Test.php">./tests/lib/Unit/</directory>
-    </testsuite>
-    <testsuite name="Integration">
-      <directory suffix="Test.php">./tests/lib/Integration/</directory>
-    </testsuite>
-    <testsuite name="Acceptance">
-      <directory suffix="Test.php">./tests/dummy/tests/</directory>
-    </testsuite>
-  </testsuites>
-  <php>
-    <ini name="error_reporting" value="E_ALL"/>
-    <ini name="memory_limit" value="256M"/>
-    <env name="APP_KEY" value="base64:BMfTqJC1cFk6A/jTPsjQgC+cROx7TDaEeGIAat6CuqY="/>
-  </php>
-  <source>
-    <include>
-      <directory suffix=".php">src/</directory>
-    </include>
-  </source>
-</phpunit>
\ No newline at end of file
+    <coverage/>
+    <testsuites>
+        <testsuite name="Unit">
+            <directory suffix="Test.php">./tests/lib/Unit/</directory>
+        </testsuite>
+        <testsuite name="Integration">
+            <directory suffix="Test.php">./tests/lib/Integration/</directory>
+        </testsuite>
+        <testsuite name="Acceptance">
+            <directory suffix="Test.php">./tests/dummy/tests/</directory>
+        </testsuite>
+    </testsuites>
+    <php>
+        <ini name="error_reporting" value="E_ALL"/>
+        <ini name="memory_limit" value="256M"/>
+        <env name="APP_KEY" value="base64:BMfTqJC1cFk6A/jTPsjQgC+cROx7TDaEeGIAat6CuqY="/>
+    </php>
+    <source>
+        <include>
+            <directory suffix=".php">src/</directory>
+        </include>
+    </source>
+</phpunit>
diff --git a/tests/dummy/tests/Feature/Avatars/ReadTest.php b/tests/dummy/tests/Feature/Avatars/ReadTest.php
index 4a835ad8..179ef537 100644
--- a/tests/dummy/tests/Feature/Avatars/ReadTest.php
+++ b/tests/dummy/tests/Feature/Avatars/ReadTest.php
@@ -75,9 +75,9 @@ public function testDownloadFileDoesNotExist(): void
             ->accept('image/*')
             ->get(url('/api/v1/avatars', $avatar));
 
-        $response
-            ->assertStatus(404)
-            ->assertHeader('Content-Type', 'text/html; charset=UTF-8');
+        $response->assertStatus(404);
+
+        $this->assertSame('text/html; charset=utf-8', strtolower($response->headers->get('Content-Type')));
     }
 
     /**
diff --git a/tests/lib/Integration/ContentNegotiation/DefaultTest.php b/tests/lib/Integration/ContentNegotiation/DefaultTest.php
index 5d6b917b..e2183bf2 100644
--- a/tests/lib/Integration/ContentNegotiation/DefaultTest.php
+++ b/tests/lib/Integration/ContentNegotiation/DefaultTest.php
@@ -108,9 +108,9 @@ public function testUnsupportedMediaType()
      */
     public function testAcceptable()
     {
-        $this->get('/api/v1/posts', ['Accept' => 'text/plain'])
-            ->assertStatus(200)
-            ->assertHeader('Content-Type', 'text/plain; charset=UTF-8');
+        $response = $this->get('/api/v1/posts', ['Accept' => 'text/plain']);
+        $response->assertStatus(200);
+        $this->assertSame('text/plain; charset=utf-8', strtolower($response->headers->get('Content-Type')));
     }
 
     /**