diff --git a/protected/humhub/modules/user/models/User.php b/protected/humhub/modules/user/models/User.php
index 35d4d34b9d..0759ccbf25 100644
--- a/protected/humhub/modules/user/models/User.php
+++ b/protected/humhub/modules/user/models/User.php
@@ -170,7 +170,7 @@ class User extends ContentContainerActiveRecord implements IdentityInterface, Se
                 return $this->isEmailRequired();
             }],
             [['guid'], 'unique'],
-            [['username'], 'validateForbiddenUsername',  'on' => [self::SCENARIO_REGISTRATION]],
+            [['username'], 'validateForbiddenUsername', 'on' => [self::SCENARIO_REGISTRATION]],
         ];
     }
 
@@ -199,7 +199,10 @@ class User extends ContentContainerActiveRecord implements IdentityInterface, Se
      */
     public function validateForbiddenUsername($attribute, $params)
     {
-        if (in_array(strtolower($this->$attribute), Yii::$app->controller->module->forbiddenUsernames)){
+        /** @var Module $module */
+        $module = Yii::$app->getModule('user');
+
+        if (in_array(strtolower($this->$attribute), $module->forbiddenUsernames)) {
             $this->addError($attribute, Yii::t('UserModule.account', 'You cannot use this username.'));
         }
     }