diff --git a/includes/class-reuna-mailchimp.php b/includes/class-reuna-mailchimp.php
index e0e05de..e760384 100644
--- a/includes/class-reuna-mailchimp.php
+++ b/includes/class-reuna-mailchimp.php
@@ -172,6 +172,7 @@ class Reuna_Mailchimp {
 
 		$this->loader->add_action( 'wp_enqueue_scripts', $plugin_public, 'enqueue_scripts' );
 		$this->loader->add_action( 'rest_api_init', $plugin_public, 'register_rest_api_routes' );
+		$this->loader->add_action( 'user_register', $plugin_public, 'create_subscriber' );
 
 	}
 
diff --git a/public/class-reuna-mailchimp-public.php b/public/class-reuna-mailchimp-public.php
index 614b4dd..cc8f423 100644
--- a/public/class-reuna-mailchimp-public.php
+++ b/public/class-reuna-mailchimp-public.php
@@ -71,6 +71,11 @@ class Reuna_Mailchimp_Public {
 	{
 		$this->plugin_name = $plugin_name;
 		$this->version = $version;
+
+		if (function_exists('env')) {
+			$this->api_key = env('MAILCHIMP_API_KEY');
+			$this->list_id = env('MAILCHIMP_LIST_ID');
+		}
 	}
 
 	/**
@@ -111,11 +116,10 @@ class Reuna_Mailchimp_Public {
 	 */
 	public function handle_rest_api_request(WP_REST_Request $request) 
 	{
-		$this->setup_environment();
-		$user = wp_get_current_user();
+		$user_id = get_current_user_id();
 
-		if (! $this->subscriber_exists($user)) {
-			$this->create_subscriber($user);
+		if (! $this->subscriber_exists($user_id)) {
+			$this->create_subscriber($user_id);
 		}
 
 		$tags = $request->get_param('tags');
@@ -123,29 +127,7 @@ class Reuna_Mailchimp_Public {
 			return;
 		}
 
-		$this->add_subscriber_tags($user, $tags);
-	}
-
-	/**
-	 * Setup class properties from environment variables
-	 *
-	 * @since    1.0.0
-	 */
-	protected function setup_environment()
-	{
-		if (! function_exists('env')) {
-			return new WP_Error('missing_env');
-		}
-
-		$this->api_key = env('MAILCHIMP_API_KEY');
-		if (! $this->api_key) {
-			return new WP_Error('missing_mailchimp_api_key');
-		}
-
-		$this->list_id = env('MAILCHIMP_LIST_ID');
-		if (! $this->list_id) {
-			return new WP_Error('missing_mailchimp_list_id');
-		}
+		$this->add_subscriber_tags($user_id, $tags);
 	}
 
 	/**
@@ -153,8 +135,10 @@ class Reuna_Mailchimp_Public {
 	 *
 	 * @since    1.0.0
 	 */
-	protected function subscriber_exists($user)
+	protected function subscriber_exists($user_id)
 	{
+		$user = get_userdata($user_id);
+
 		$mailchimp =  new Mailchimp($this->api_key);
 		$subscriber_hash = MailChimp::subscriberHash($user->user_email);
 
@@ -168,8 +152,10 @@ class Reuna_Mailchimp_Public {
 	 *
 	 * @since    1.0.0
 	 */
-	protected function add_subscriber_tags(WP_User $user, array $tags)
+	protected function add_subscriber_tags($user_id, array $tags)
 	{
+		$user = get_userdata($user_id);
+		
 		$mailchimp =  new Mailchimp($this->api_key);
 		$subscriber_hash = MailChimp::subscriberHash($user->user_email);
 
@@ -194,8 +180,10 @@ class Reuna_Mailchimp_Public {
 	 *
 	 * @since    1.0.0
 	 */
-	protected function create_subscriber(WP_User $user)
+	public function create_subscriber(int $user_id)
 	{
+		$user = get_userdata($user_id);
+
 		$mailchimp = new Mailchimp($this->api_key);
 
 		$options = [