diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..ca50ddd
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,15 @@
+version: 2
+updates:
+  - package-ecosystem: composer
+    directory: /
+    schedule:
+      interval: weekly
+    groups:
+      composer-minor:
+        update-types:
+          - minor
+          - patch
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index b6ec473..6ee9820 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -39,7 +39,7 @@ jobs:
     needs: [ install_dependencies ]
     strategy:
       matrix:
-        php-versions: [ "7.4", "8.0", "8.1", "8.2", "8.3", "8.4" ]
+        php-versions: [ "7.4", "8.0", "8.1", "8.2", "8.3", "8.4", "8.5" ]
 
     runs-on: ubuntu-latest
 
diff --git a/bump_version.sh b/bump_version.sh
index 8872e6e..a0e3169 100755
--- a/bump_version.sh
+++ b/bump_version.sh
@@ -17,7 +17,7 @@ new_version=${1#v}
 
 echo "New version: $new_version"
 
-if ! [[ "$new_version" =~ ^[0-9]+\.[0-9]+\.[0-9](-[a-z]+\.[0-9]+)?$ ]]
+if ! [[ "$new_version" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-[a-z]+\.[0-9]+)?$ ]]
 then
   echo "Invalid version format. Please use semantic versioning (https://semver.org/)."
   exit 1
diff --git a/composer.json b/composer.json
index 4e20523..bd01e90 100644
--- a/composer.json
+++ b/composer.json
@@ -36,7 +36,7 @@
     },
     "require-dev": {
         "phpunit/phpunit": "^9.0",
-        "phpstan/phpstan": "^1",
+        "phpstan/phpstan": "^2.2",
         "mockery/mockery": "^1.5",
         "php-cs-fixer/shim": "^3.87",
         "psr/http-client": "^1.0",
diff --git a/src/Connection.php b/src/Connection.php
index f501266..16133b3 100644
--- a/src/Connection.php
+++ b/src/Connection.php
@@ -24,7 +24,7 @@
  */
 class Connection
 {
-    public const VERSION = '3.0.0';
+    public const VERSION = '3.0.1';
 
     public const BASE_URL = 'https://app.sendy.nl';
 
@@ -63,8 +63,8 @@ class Connection
     /** @var mixed */
     private $state = null;
 
-    /** @var callable($this) */
-    private $tokenUpdateCallback;
+    /** @var (callable(self): void)|null */
+    private $tokenUpdateCallback = null;
 
     private bool $oauthClient = false;
 
diff --git a/src/Http/Response.php b/src/Http/Response.php
index 0717c9e..5a81f29 100644
--- a/src/Http/Response.php
+++ b/src/Http/Response.php
@@ -88,11 +88,24 @@ final class Response
     public function __construct(int $statusCode, array $headers, string $body)
     {
         $this->statusCode = $statusCode;
-        $this->headers = array_map(
-            fn($value) => is_array($value) ? $value : [$value],
+        $this->headers = $this->normalizeHeaders($headers);
+        $this->body = $body;
+    }
+
+    /**
+     * Lowercase the header names and strip CR and LF from the values, so
+     * consumers can safely emit headers in their own HTTP responses without
+     * risking header injection.
+     *
+     * @param array<string, list<string>|string> $headers
+     * @return array<string, list<string>>
+     */
+    private function normalizeHeaders(array $headers): array
+    {
+        return array_map(
+            fn($value) => str_replace(["\r", "\n"], '', is_array($value) ? $value : [$value]),
             array_change_key_case($headers, CASE_LOWER),
         );
-        $this->body = $body;
     }
 
     public function getStatusCode(): int
diff --git a/src/Http/Transport/MockTransport.php b/src/Http/Transport/MockTransport.php
index 15ea0b5..1c00337 100644
--- a/src/Http/Transport/MockTransport.php
+++ b/src/Http/Transport/MockTransport.php
@@ -7,7 +7,7 @@
 
 class MockTransport implements TransportInterface
 {
-    private ?Response $response;
+    private Response $response;
 
     /**
      * @var list<Request>
diff --git a/tests/ConnectionTest.php b/tests/ConnectionTest.php
index b30a84e..0f63480 100644
--- a/tests/ConnectionTest.php
+++ b/tests/ConnectionTest.php
@@ -6,7 +6,6 @@
 use Sendy\Api\ApiException;
 use Sendy\Api\Connection;
 use Sendy\Api\Exceptions\ClientException;
-use Sendy\Api\Exceptions\SendyException;
 use Sendy\Api\Http\Request;
 use Sendy\Api\Http\Response;
 use Sendy\Api\Http\Transport\MockTransport;
@@ -16,6 +15,11 @@
 
 class ConnectionTest extends TestCase
 {
+    public function testVersionUsesSemverFormat(): void
+    {
+        $this->assertMatchesRegularExpression('/^\d+\.\d+\.\d+(-[a-z]+\.\d+)?$/', Connection::VERSION);
+    }
+
     public function testUserAgentIsSet(): void
     {
         $phpVersion = phpversion();
@@ -23,21 +27,21 @@ public function testUserAgentIsSet(): void
 
         $connection = $this->createConnection();
         $this->assertEquals(
-            "SendySDK/3.0.0 PHP/{$phpVersion} curl/{$curlVersion}",
+            "SendySDK/" . Connection::VERSION . " PHP/{$phpVersion} curl/{$curlVersion}",
             $connection->createRequest('GET', '/')->getHeaders()['user-agent'],
         );
 
         $connection = $this->createConnection();
         $connection->setUserAgentAppendix('WooCommerce/6.2');
         $this->assertEquals(
-            "SendySDK/3.0.0 PHP/{$phpVersion} curl/{$curlVersion} WooCommerce/6.2",
+            "SendySDK/" . Connection::VERSION . " PHP/{$phpVersion} curl/{$curlVersion} WooCommerce/6.2",
             $connection->createRequest('GET', '/')->getHeaders()['user-agent'],
         );
 
         $connection = $this->createConnection();
         $connection->setOauthClient(true);
         $this->assertEquals(
-            "SendySDK/3.0.0 PHP/{$phpVersion} OAuth/2.0 curl/{$curlVersion}",
+            "SendySDK/" . Connection::VERSION . " PHP/{$phpVersion} OAuth/2.0 curl/{$curlVersion}",
             $connection->createRequest('GET', '/')->getHeaders()['user-agent'],
         );
     }
@@ -133,6 +137,25 @@ public function testParseResponseExtractsMeta(): void
         $this->assertInstanceOf(Meta::class, $connection->meta);
     }
 
+    public function testParseResponseExposesOnlySendyHeadersWithSanitizedValues(): void
+    {
+        $connection = new Connection();
+
+        $response = new Response(200, [
+            'content-type' => ['application/json'],
+            'X-Sendy-Token' => ["secret\r\nx-injected: value"],
+            'x-sendy-shipment-id' => ['123'],
+            'x-ratelimit-remaining' => ['59'],
+        ], json_encode(['data' => []]));
+
+        $connection->parseResponse($response, new Request('GET', '/foo'));
+
+        $this->assertEquals([
+            'x-sendy-token' => ['secretx-injected: value'],
+            'x-sendy-shipment-id' => ['123'],
+        ], $connection->sendyHeaders);
+    }
+
     public function testParseResponseUnwrapsData(): void
     {
         $connection = new Connection();
@@ -234,13 +257,10 @@ public function testRevokedRefreshTokenIsHandled(): void
         $connection->setRefreshToken('RefreshToken');
         $connection->setTokenExpires(time() + 5);
 
-        try {
-            $connection->checkOrAcquireAccessToken();
-        } catch (SendyException $exception) {
-            $this->fail($exception->getMessage());
-        }
+        $connection->checkOrAcquireAccessToken();
 
-        $this->assertTrue(true);
+        $this->assertSame('accessToken', $connection->getAccessToken());
+        $this->assertSame('RefreshToken', $connection->getRefreshToken());
     }
 
     public function testUnexpectedExceptionWhenRefreshingTokensAreHandled(): void