diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 68b3820..bbd2a06 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -17,12 +17,21 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php: ['7.4', '8.0', '8.1', '8.2', '8.3']
+        php: ['7.4', '8.0', '8.1', '8.2', '8.3', '8.4', '8.5']
         codeception: ['^4.0', '^5.0']
+        deps: ['lowest', 'latest']
         exclude:
           # Codeception 5 requires PHP ≥ 8
           - php: '7.4'
             codeception: '^5.0'
+          # PHP >= 8.5 will not run Codeception 4
+          - php: '8.5'
+            codeception: '^4.0'
+            deps: 'lowest'
+          # PHP >= 8.5 will not run Codeception 4
+          - php: '8.5'
+            codeception: '^4.0'
+            deps: 'latest'
 
     steps:
       - uses: actions/checkout@v4
@@ -42,9 +51,11 @@ jobs:
           ini-values: "sendmail_path = /usr/bin/env catchmail -f some@from.address"
           php-version: ${{ matrix.php }}
       - uses: ramsey/composer-install@v3
+        env:
+          COMPOSER_POLICY_ADVISORIES_BLOCK: 0
         with:
-          dependency-versions: highest
-          composer-options: "--with=codeception/codeception:${{ matrix.codeception }}"
+          dependency-versions: ${{ matrix.deps }}
+          composer-options: "--with=codeception/codeception:${{ matrix.codeception }} ${{ case(matrix.php == '8.5', '--with codeception/codeception:>=5.3.4', '') }} ${{ case(matrix.codeception == '^4.0', '--with=behat/gherkin:<4.13', '') }} ${{ case(matrix.php == '7.4', '', '--with=symfony/yaml:>=2.8.0 --with=phpunit/phpunit:>=9.6') }}"
       - run: php vendor/bin/codecept build
       - name: Acceptance tests
         run: php vendor/bin/codecept run acceptance -d
diff --git a/composer.json b/composer.json
index 1fb3d08..0cf57c8 100644
--- a/composer.json
+++ b/composer.json
@@ -15,9 +15,9 @@
     "require": {
         "php": "^7.4 || ^8.0",
         "ext-json": "*",
-        "guzzlehttp/guzzle": "^6.0 || ^7.0",
+        "guzzlehttp/guzzle": "^6.3 || ^7.0 || ^8.0",
         "codeception/codeception": "^4.0 || ^5.0",
-        "zbateson/mail-mime-parser": "^1.2"
+        "zbateson/mail-mime-parser": "^1.3.1 || ^2.0 || ^3.0 || ^4.0"
     },
     "autoload": {
         "psr-4": {
@@ -25,7 +25,7 @@
         }
     },
     "require-dev": {
-        "codeception/module-asserts": "^1.1 || ^2",
+        "codeception/module-asserts": "^1.3.1 || ^2",
         "phpmailer/phpmailer": "^6.1.6"
     },
     "suggest": {
diff --git a/src/Module/MailCatcher.php b/src/Module/MailCatcher.php
index f8fa4d5..05b0b1c 100644
--- a/src/Module/MailCatcher.php
+++ b/src/Module/MailCatcher.php
@@ -308,7 +308,7 @@ public function grabUrlsFromLastEmail(): array
         $regex = '#\bhttps?://[^,\s()<>]+(?:\([\w\d]+\)|([^,[:punct:]\s]|/))#';
         $email = $this->lastMessage();
 
-        $message = Message::from($email->getSource());
+        $message = Message::from($email->getSource(), false);
 
         $text = $message->getTextContent();
         preg_match_all($regex, $text, $text_matches);
@@ -331,7 +331,7 @@ public function grabAttachmentsFromLastEmail(): array
     {
         $email = $this->lastMessage();
 
-        $message = Message::from($email->getSource());
+        $message = Message::from($email->getSource(), false);
 
         $attachments = [];
 
@@ -354,7 +354,7 @@ public function grabAttachmentsFromLastEmail(): array
     public function seeAttachmentInLastEmail(string $expectedFilename): void
     {
         $email = $this->lastMessage();
-        $message = Message::from($email->getSource());
+        $message = Message::from($email->getSource(), false);
 
         foreach ($message->getAllAttachmentParts() as $attachmentPart) {
             if ($attachmentPart->getFilename() === $expectedFilename) {
@@ -384,7 +384,7 @@ public function seeEmailCount(int $expected): void
     public function seeEmailAttachmentCount(int $expectedCount): void
     {
         $email = $this->lastMessage();
-        $message = Message::from($email->getSource());
+        $message = Message::from($email->getSource(), false);
         $this->assertEquals($expectedCount, $message->getAttachmentCount());
     }