diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5a81b22f..30a2fae6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,10 +9,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- New method `Redmine\Api\Attachment::update()` for updating attachments.
 - New interface `Redmine\Http\HttpClient` for new minimalistic HTTP clients.
 - New interface `Redmine\Http\Request` for sending data with new minimalistic HTTP clients.
 - New method `Redmine\Api\...::getLastResponse()` to get the last response made by the API class.
-- Add support for custom arrays in `Redmine\Serializer\XmlSerializer`
+- Add support for custom arrays in `Redmine\Serializer\XmlSerializer`.
 
 ### Changed
 
diff --git a/src/Redmine/Api/Attachment.php b/src/Redmine/Api/Attachment.php
index 6ad17939..bc5e33b1 100644
--- a/src/Redmine/Api/Attachment.php
+++ b/src/Redmine/Api/Attachment.php
@@ -3,6 +3,7 @@
 namespace Redmine\Api;
 
 use Redmine\Exception\SerializerException;
+use Redmine\Exception\UnexpectedResponseException;
 use Redmine\Http\HttpFactory;
 use Redmine\Serializer\JsonSerializer;
 use Redmine\Serializer\PathSerializer;
@@ -46,6 +47,39 @@ public function show($id)
         }
     }
 
+    /**
+     * Update information about an attachment.
+     *
+     * @see https://www.redmine.org/projects/redmine/wiki/Rest_Attachments#PATCH
+     *
+     * @param int $id the attachment id
+     * @param array $params available $params:
+     *   - filename: filename of the attachment
+     *   - description: new description of the attachment
+     *
+     * @throws SerializerException if $params contains invalid values
+     * @throws UnexpectedResponseException if the Redmine server delivers an unexpected response
+     *
+     * @return true if the request was successful
+     */
+    final public function update(int $id, array $params): bool
+    {
+        // we are using `PUT` instead of documented `PATCH`
+        // @see https://github.com/kbsali/php-redmine-api/pull/395#issuecomment-2004089154
+        // @see https://www.redmine.org/projects/redmine/wiki/Rest_Attachments#PATCH
+        $this->lastResponse = $this->getHttpClient()->request(HttpFactory::makeJsonRequest(
+            'PUT',
+            '/attachments/' . $id . '.json',
+            JsonSerializer::createFromArray(['attachment' => $params])->getEncoded()
+        ));
+
+        if ($this->lastResponse->getStatusCode() !== 204) {
+            throw UnexpectedResponseException::create($this->lastResponse);
+        }
+
+        return true;
+    }
+
     /**
      * Get attachment content as a binary file.
      *
diff --git a/tests/Behat/Bootstrap/AttachmentContextTrait.php b/tests/Behat/Bootstrap/AttachmentContextTrait.php
index 63a86b75..be47608d 100644
--- a/tests/Behat/Bootstrap/AttachmentContextTrait.php
+++ b/tests/Behat/Bootstrap/AttachmentContextTrait.php
@@ -4,7 +4,6 @@
 
 namespace Redmine\Tests\Behat\Bootstrap;
 
-use Behat\Behat\Tester\Exception\PendingException;
 use Behat\Gherkin\Node\TableNode;
 use Redmine\Api\Attachment;
 
@@ -32,6 +31,26 @@ public function iUploadTheContentOfTheFileWithTheFollowingData(string $filepath,
         );
     }
 
+    /**
+     * @When I update the attachment with the id :attachmentId with the following data
+     */
+    public function iUpdateTheAttachmentWithTheIdWithTheFollowingData(int $attachmentId, TableNode $table)
+    {
+        $data = [];
+
+        foreach ($table as $row) {
+            $data[$row['property']] = $row['value'];
+        }
+
+        /** @var Attachment */
+        $api = $this->getNativeCurlClient()->getApi('attachment');
+
+        $this->registerClientResponse(
+            $api->update($attachmentId, $data),
+            $api->getLastResponse()
+        );
+    }
+
     /**
      * @When I show the attachment with the id :attachmentId
      */
diff --git a/tests/Behat/features/attachments.feature b/tests/Behat/features/attachments.feature
index da303c56..aef9a26b 100644
--- a/tests/Behat/features/attachments.feature
+++ b/tests/Behat/features/attachments.feature
@@ -26,6 +26,21 @@ Feature: Interacting with the REST API for attachments
             | id                | 1                                                                  |
             | token             | 1.7b962f8af22e26802b87abfa0b07b21dbd03b984ec8d6888dabd3f69cff162f8 |
 
+    @attachment
+    Scenario: Updating the details of an attachment
+        Given I have a "NativeCurlClient" client
+        And I create a project with name "Test Project" and identifier "test-project"
+        And I upload the content of the file "%tests_dir%/Fixtures/testfile_01.txt" with the following data
+            | property          | value                |
+            | filename          | testfile.txt         |
+        When I update the attachment with the id "1" with the following data
+            | property          | value                |
+            | filename          | testfile2.txt        |
+        Then the response has the status code "204"
+        And the response has an empty content type
+        And the response has the content ""
+        And the returned data is true
+
     @attachment
     Scenario: Showing the details of an attachment
         Given I have a "NativeCurlClient" client
diff --git a/tests/Unit/Api/Attachment/UpdateTest.php b/tests/Unit/Api/Attachment/UpdateTest.php
new file mode 100644
index 00000000..df6c43b1
--- /dev/null
+++ b/tests/Unit/Api/Attachment/UpdateTest.php
@@ -0,0 +1,79 @@
+<?php
+
+namespace Redmine\Tests\Unit\Api\Attachment;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\TestCase;
+use Redmine\Api\Attachment;
+use Redmine\Exception\UnexpectedResponseException;
+use Redmine\Tests\Fixtures\AssertingHttpClient;
+
+#[CoversClass(Attachment::class)]
+class UpdateTest extends TestCase
+{
+    /**
+     * @dataProvider getUpdateData
+     */
+    #[DataProvider('getUpdateData')]
+    public function testUpdateReturnsCorrectResponse($id, array $params, $expectedPath, $expectedContent, $expectedReturn)
+    {
+        $client = AssertingHttpClient::create(
+            $this,
+            [
+                'PUT',
+                $expectedPath,
+                'application/json',
+                $expectedContent,
+                204,
+                '',
+                ''
+            ]
+        );
+
+        // Create the object under test
+        $api = new Attachment($client);
+
+        // Perform the tests
+        $this->assertSame($expectedReturn, $api->update($id, $params));
+    }
+
+    public static function getUpdateData(): array
+    {
+        return [
+            'test with all params' => [
+                5,
+                [
+                    'filename' => 'renamed.zip',
+                    'description' => 'updated',
+                ],
+                '/attachments/5.json',
+                '{"attachment":{"filename":"renamed.zip","description":"updated"}}',
+                true,
+            ],
+        ];
+    }
+
+    public function testUpdateThrowsUnexpectedResponseException()
+    {
+        $client = AssertingHttpClient::create(
+            $this,
+            [
+                'PUT',
+                '/attachments/5.json',
+                'application/json',
+                '{"attachment":[]}',
+                403,
+                '',
+                '',
+            ]
+        );
+
+        $api = new Attachment($client);
+
+        $this->expectException(UnexpectedResponseException::class);
+        $this->expectExceptionMessage('The Redmine server replied with an unexpected response.');
+
+        $api->update(5, []);
+    }
+}