diff --git a/lib/Subscription/CaptchaSession.php b/lib/Subscription/CaptchaSession.php
index b1cd634afe..99bb442c12 100644
--- a/lib/Subscription/CaptchaSession.php
+++ b/lib/Subscription/CaptchaSession.php
@@ -2,11 +2,12 @@
 
 namespace MailPoet\Subscription;
 
-use MailPoet\Config\Session;
+use MailPoet\Util\Security;
 use MailPoet\WP\Functions as WPFunctions;
 
 class CaptchaSession {
   const EXPIRATION = 1800; // 30 minutes
+  const ID_LENGTH = 32;
 
   const SESSION_HASH_KEY = 'hash';
   const SESSION_FORM_KEY = 'form';
@@ -14,16 +15,22 @@ class CaptchaSession {
   /** @var WPFunctions */
   private $wp;
 
-  /** @var Session */
-  private $session;
+  /** @var string */
+  private $id;
 
-  function __construct(WPFunctions $wp, Session $session) {
+  function __construct(WPFunctions $wp) {
     $this->wp = $wp;
-    $this->session = $session;
   }
 
-  function isAvailable() {
-    return $this->session->getId() !== null;
+  function init($id = null) {
+    $this->id = $id ?: Security::generateRandomString(self::ID_LENGTH);
+  }
+
+  function getId() {
+    if ($this->id === null) {
+      throw new \Exception("MailPoet captcha session not initialized.");
+    }
+    return $this->id;
   }
 
   function reset() {
@@ -48,10 +55,6 @@ class CaptchaSession {
   }
 
   private function getKey($type) {
-    $session_id = $this->session->getId();
-    if ($session_id === null) {
-      throw new \Exception("MailPoet session not initialized.");
-    }
-    return implode('_', ['MAILPOET', $session_id, $type]);
+    return implode('_', ['MAILPOET', $this->getId(), $type]);
   }
 }
diff --git a/tests/integration/Subscription/CaptchaSessionTest.php b/tests/integration/Subscription/CaptchaSessionTest.php
index f7e5d2490f..50dd50b22b 100644
--- a/tests/integration/Subscription/CaptchaSessionTest.php
+++ b/tests/integration/Subscription/CaptchaSessionTest.php
@@ -1,61 +1,33 @@
 <?php
 namespace MailPoet\Test\Subscription;
 
-use MailPoet\Config\Session;
 use MailPoet\Subscription\CaptchaSession;
-use MailPoet\Util\Cookies;
 use MailPoet\WP\Functions as WPFunctions;
-use PHPUnit_Framework_MockObject_MockObject as MockObject;
 
 class CaptchaSessionTest extends \MailPoetTest {
+  const SESSION_ID = 'ABCD';
 
   /** @var CaptchaSession */
   private $captcha_session;
 
-  /** @var MockObject */
-  private $cookies_mock;
-
   function _before() {
-    $this->cookies_mock = $this->createMock(Cookies::class);
-    $this->captcha_session = new CaptchaSession(new WPFunctions, new Session($this->cookies_mock));
-  }
-
-  function testIsAvailableWhenCookieExists() {
-    $this->cookies_mock
-      ->method('get')
-      ->willReturn('abcd');
-    expect($this->captcha_session->isAvailable())->true();
-  }
-
-  function testIsNotAvailableWhenCookieDoesntExits() {
-    $this->cookies_mock
-      ->method('get')
-      ->willReturn(null);
-    expect($this->captcha_session->isAvailable())->false();
+    $this->captcha_session = new CaptchaSession(new WPFunctions);
+    $this->captcha_session->init(self::SESSION_ID);
   }
 
   function testItCanStoreAndRetrieveFormData() {
-    $this->cookies_mock
-      ->method('get')
-      ->willReturn('abcd');
     $form_data = ['email' => 'email@example.com'];
     $this->captcha_session->setFormData($form_data);
     expect($this->captcha_session->getFormData())->equals($form_data);
   }
 
   function testItCanStoreAndRetrieveCaptchaHash() {
-    $this->cookies_mock
-      ->method('get')
-      ->willReturn('abcd');
     $hash = '1234';
     $this->captcha_session->setCaptchaHash($hash);
     expect($this->captcha_session->getCaptchaHash())->equals($hash);
   }
 
   function testItCanResetSessionData() {
-    $this->cookies_mock
-      ->method('get')
-      ->willReturn('abcd');
     $this->captcha_session->setFormData(['email' => 'email@example.com']);
     $this->captcha_session->setCaptchaHash('hash123');
     $this->captcha_session->reset();
@@ -64,15 +36,12 @@ class CaptchaSessionTest extends \MailPoetTest {
   }
 
   function testItAssociatesDataWithSession() {
-    $session1 = 'abcd';
-    $session2 = 'efgh';
-    $this->cookies_mock
-      ->method('get')
-      ->willReturnOnConsecutiveCalls($session1, $session1, $session2, $session1);
     $hash = '1234';
     $this->captcha_session->setCaptchaHash($hash);
     expect($this->captcha_session->getCaptchaHash())->equals($hash);
+    $this->captcha_session->init();
     expect($this->captcha_session->getCaptchaHash())->false();
+    $this->captcha_session->init(self::SESSION_ID);
     expect($this->captcha_session->getCaptchaHash())->equals($hash);
   }
 }