diff --git a/main/inc/lib/usermanager.lib.php b/main/inc/lib/usermanager.lib.php
index 5b6a4cb1b4..3466dee90e 100755
--- a/main/inc/lib/usermanager.lib.php
+++ b/main/inc/lib/usermanager.lib.php
@@ -210,7 +210,7 @@ class UserManager
                     $phoneNumber = isset($extra['mobile_phone_number']) ? $extra['mobile_phone_number'] : null;
                     $plugin = new AppPlugin();
                     $additionalParameters = array(
-                        'smsType' => constant($plugin->getSMSPluginName().'::WELCOME_LOGIN_PASSWORD'),
+                        'smsType' => @constant($plugin->getSMSPluginName().'::WELCOME_LOGIN_PASSWORD'),
                         'userId' => $return,
                         'mobilePhoneNumber' => $phoneNumber,
                         'password' => $original_password