diff --git a/Classes/Controller/FrontendUserController.php b/Classes/Controller/FrontendUserController.php
index 0dd7d60..d7f1696 100644
--- a/Classes/Controller/FrontendUserController.php
+++ b/Classes/Controller/FrontendUserController.php
@@ -7,6 +7,7 @@
 use TYPO3\CMS\Core\Crypto\PasswordHashing\PasswordHashFactory;
 use TYPO3\CMS\Core\Crypto\Random;
 use TYPO3\CMS\Core\Mail\MailMessage;
+use TYPO3\CMS\Core\Type\ContextualFeedbackSeverity;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 use TYPO3\CMS\Extbase\Http\ForwardResponse;
 use TYPO3\CMS\Extbase\Mvc\Controller\ActionController;
@@ -43,6 +44,16 @@ public function newAction(?FrontendUser $newFrontendUser = null): ResponseInterf
 
     public function createAction(FrontendUser $newFrontendUser): ResponseInterface
     {
+        if ($this->settings['captcha']['sitekey'] !== '' && $this->settings['captcha']['secretkey'] !== '') {
+            if ($this->verifyCaptcha() === false) {
+                $this->addFlashMessage(
+                    LocalizationUtility::translate('error.captcha', 'newsletterregistration'),
+                    '',
+                    ContextualFeedbackSeverity::ERROR
+                );
+                return new ForwardResponse('new');
+            }
+        }
         /** @var FrontendUser $existingFrontendUser */
         $existingFrontendUser = $this->frontendUserRepository->findOneByEmailAndStoragePageId(
             $newFrontendUser->getEmail(),
@@ -292,6 +303,43 @@ protected function getRandomPassword(): string
         return $hashInstance->getHashedPassword($randomPassword);
     }
 
+    protected function verifyCaptcha(): bool
+    {
+        $sitekey = $this->settings['captcha']['sitekey'] ?? '';
+        $secretkey = $this->settings['captcha']['secretkey'] ?? '';
+
+        if (empty($secretkey)) {
+            return true;
+        }
+
+        $parsedBody = $this->request->getParsedBody();
+        $parsedBody = is_array($parsedBody) ? $parsedBody : [];
+        $solution = $parsedBody['frc-captcha-solution'] ?? '';
+        if (empty($solution) || $solution === '.UNSTARTED' || $solution === '.FETCHING') {
+            return false;
+        }
+
+        try {
+            $requestFactory = GeneralUtility::makeInstance(\TYPO3\CMS\Core\Http\RequestFactory::class);
+            $response = $requestFactory->request(
+                'https://eu-api.friendlycaptcha.eu/api/v1/siteverify',
+                'POST',
+                [
+                    'headers' => ['Content-Type' => 'application/json; charset=UTF-8'],
+                    'body' => json_encode([
+                        'solution' => $solution,
+                        'secret' => $secretkey,
+                        'sitekey' => $sitekey,
+                    ]),
+                ]
+            );
+            $data = json_decode((string)$response->getBody(), true);
+            return ($data['success'] ?? false) === true;
+        } catch (\Throwable $e) {
+            return false;
+        }
+    }
+
     protected function getHashedPassword(string $password): string
     {
         $hashInstance = GeneralUtility::makeInstance(PasswordHashFactory::class)->getDefaultHashInstance('FE');
diff --git a/Configuration/TypoScript/setup.typoscript b/Configuration/TypoScript/setup.typoscript
index bc087a8..5837289 100644
--- a/Configuration/TypoScript/setup.typoscript
+++ b/Configuration/TypoScript/setup.typoscript
@@ -14,6 +14,10 @@ plugin.tx_newsletterregistration {
     skipDefaultArguments = 1
   }
   settings {
+    captcha {
+      sitekey =
+      secretkey =
+    }
     sender {
       name = My organization
       email = no_reply@example.org
diff --git a/Resources/Private/Language/de.locallang.xlf b/Resources/Private/Language/de.locallang.xlf
index 0f88b68..c299524 100644
--- a/Resources/Private/Language/de.locallang.xlf
+++ b/Resources/Private/Language/de.locallang.xlf
@@ -159,6 +159,10 @@
 				<source>Organisation</source>
 				<target>Organisation</target>
 			</trans-unit>
+			<trans-unit id="error.captcha">
+				<source>Captcha verification failed. Please try again.</source>
+				<target>Captcha-Überprüfung fehlgeschlagen. Bitte versuchen Sie es erneut.</target>
+			</trans-unit>
 		</body>
 	</file>
 </xliff>
diff --git a/Resources/Private/Language/locallang.xlf b/Resources/Private/Language/locallang.xlf
index 92b6d9e..e5a4466 100644
--- a/Resources/Private/Language/locallang.xlf
+++ b/Resources/Private/Language/locallang.xlf
@@ -118,6 +118,9 @@
 			<trans-unit id="labels.company">
 				<source>Organisation</source>
 			</trans-unit>
+			<trans-unit id="error.captcha">
+				<source>Captcha verification failed. Please try again.</source>
+			</trans-unit>
 		</body>
 	</file>
 </xliff>
diff --git a/Resources/Private/Templates/FrontendUser/New.html b/Resources/Private/Templates/FrontendUser/New.html
index 5330e7c..147232a 100644
--- a/Resources/Private/Templates/FrontendUser/New.html
+++ b/Resources/Private/Templates/FrontendUser/New.html
@@ -13,6 +13,32 @@
 			</label>
 			<f:form.textfield id="email" class="form-control" property="email" required="required" />
 		</div>
+		<f:if condition="{settings.captcha.sitekey} !== '' && {settings.captcha.secretkey} !== ''">
+			<f:asset.script identifier="friendly-challenge-widget-module"
+				src="https://cdn.jsdelivr.net/npm/friendly-challenge@0.9.8/widget.module.min.js"
+				type="module"
+				integrity="sha384-qT4bq9FARVVEQZ+u0J/IEGVVCM/d/aU6p2anikjcUPeSd9n5QP8xJ5wxyf3kvrUU"
+				crossorigin="anonymous"
+				async="true"
+				defer="true"
+				useNonce="true"
+			/>
+			<f:asset.script identifier="friendly-challenge-widget"
+				src="https://cdn.jsdelivr.net/npm/friendly-challenge@0.9.8/widget.min.js"
+				nomodule="true"
+				integrity="sha384-tBCxcMwFwX1Y+iL38Da2IZLdhA3HPO3ztLc4sD5ZYK4CgH4mTb0fRPwOw/4GEb12"
+				crossorigin="anonymous"
+				async="true"
+				defer="true"
+				useNonce="true"
+			/>
+			<div class="form-group">
+				<div class="frc-captcha"
+					data-puzzle-endpoint="https://eu-api.friendlycaptcha.eu/api/v1/puzzle"
+					data-sitekey="{settings.captcha.sitekey}">
+				</div>
+			</div>
+		</f:if>
 		<div class="form-group">
 			<f:form.submit value="{f:translate(key:'newFrontendUser.submit')}" />
 		</div>