diff --git a/cleantalk.php b/cleantalk.php
index 0293d247..909158b7 100644
--- a/cleantalk.php
+++ b/cleantalk.php
@@ -11,6 +11,7 @@
   Domain Path: /i18n
 */
 
+use Cleantalk\Antispam\ProtectByShortcode;
 use Cleantalk\ApbctWP\Activator;
 use Cleantalk\ApbctWP\AdminNotices;
 use Cleantalk\ApbctWP\Antispam\EmailEncoder;
@@ -366,6 +367,9 @@ function apbct_alt_session__save__WP_AJAX()
 require_once(CLEANTALK_PLUGIN_DIR . 'inc/cleantalk-integrations-by-hook.php');
 require_once(CLEANTALK_PLUGIN_DIR . 'inc/cleantalk-integrations-by-class.php');
 
+// Form protection by shortcode
+new ProtectByShortcode();
+
 // WP Delicious integration
 add_filter('delicious_recipes_process_registration_errors', 'apbct_wp_delicious', 10, 4);
 
diff --git a/lib/Cleantalk/Antispam/ProtectByShortcode.php b/lib/Cleantalk/Antispam/ProtectByShortcode.php
new file mode 100644
index 00000000..46de7de1
--- /dev/null
+++ b/lib/Cleantalk/Antispam/ProtectByShortcode.php
@@ -0,0 +1,64 @@
+<?php
+
+namespace Cleantalk\Antispam;
+
+use Cleantalk\ApbctWP\Variables\Server;
+
+class ProtectByShortcode
+{
+    public function __construct()
+    {
+        global $apbct;
+
+        if ((int)$apbct->settings['forms__contact_forms_test'] === 1) {
+            add_filter('ct_wordpress_protect_from_spam', array($this, 'protectByShortcode'), 10, 2);
+        }
+    }
+
+    /**
+     * A function to protect the data of $_POST, $_GET custom forms by the ct_wordpress_protect_from_spam hook.
+     * Returns an array with the result of the check. Also, if $options['redirect_to_block_page'] = 1 is passed,
+     * a redirect will be made to the blocking page.
+     * @param array $data
+     * @param array $options
+     * @return array
+     * @psalm-suppress PossiblyUnusedReturnValue
+     */
+    public function protectByShortcode($data, $options = [])
+    {
+        $output = [
+            'is_spam' => false,
+            'message' => '',
+        ];
+
+        $input_array = apply_filters('apbct__filter_post', $data);
+        $data = ct_gfa($input_array);
+
+        $base_call_data = array(
+            'message'         => ! empty($data['message']) ? json_encode($data['message']) : '',
+            'sender_email'    => ! empty($data['email']) ? $data['email'] : '',
+            'sender_nickname' => ! empty($data['nickname']) ? $data['nickname'] : '',
+            'event_token'     => ! empty($data['event_token']) ? $data['event_token'] : '',
+            'post_info'       => array(
+                'post_url'     => Server::get('HTTP_REFERER'),
+            ),
+        );
+        $result = apbct_base_call($base_call_data, false);
+        $ct_result = isset($result['ct_result']) ? $result['ct_result'] : null;
+
+        $is_spam = $ct_result !== null && $ct_result->allow !== 1;
+
+        if (isset($options['redirect_to_block_page']) && $options['redirect_to_block_page'] && $is_spam) {
+            wp_die(isset($ct_result->comment) ? $ct_result->comment : __('Blocked by CleanTalk'), __('Forbidden'), array('response' => 403));
+        }
+
+        if ($is_spam) {
+            $output = [
+                'is_spam' => true,
+                'message' => $ct_result->comment,
+            ];
+        }
+
+        return $output;
+    }
+}