diff --git a/main/auth/courses.php b/main/auth/courses.php
index 492e3c8826..82db4b619a 100755
--- a/main/auth/courses.php
+++ b/main/auth/courses.php
@@ -210,6 +210,13 @@ switch ($action) {
         $courses_controller->sessionsList($action, $nameTools, $limit);
         break;
     case 'subscribe_to_session':
+        $userId = api_get_user_id();
+
+        if (empty($userId)) {
+            header('Location: ' . api_get_path(WEB_PATH));
+            exit;
+        }
+
         $registrationAllowed = api_get_setting('catalog_allow_session_auto_subscription');
         if ($registrationAllowed === 'true') {
             $entityManager = Database::getManager();
@@ -224,7 +231,7 @@ switch ($action) {
                 $requirementsData = SequenceResourceManager::checkRequirementsForUser(
                     $sequences,
                     SequenceResource::SESSION_TYPE,
-                    api_get_user_id()
+                    $userId
                 );
 
                 $continueWithSubscription = SequenceResourceManager::checkSequenceAreCompleted($requirementsData);
@@ -237,7 +244,7 @@ switch ($action) {
 
             SessionManager::suscribe_users_to_session(
                 $_GET['session_id'],
-                array($_GET['user_id'])
+                array($userId)
             );
 
             $coursesList = SessionManager::get_course_list_by_session_id($_GET['session_id']);
diff --git a/main/auth/courses_controller.php b/main/auth/courses_controller.php
index 56b9124cbc..ae75ebead3 100755
--- a/main/auth/courses_controller.php
+++ b/main/auth/courses_controller.php
@@ -534,8 +534,7 @@ class CoursesController
             $url .= 'auth/courses.php?';
             $url .= http_build_query([
                 'action' => 'subscribe_to_session',
-                'session_id' => intval($sessionId),
-                'user_id' => api_get_user_id()
+                'session_id' => intval($sessionId)
             ]);
         } else {
             $url .= 'inc/email_editor.php?';