yii2-rbac-plus PHP fatal error yii\base\ErrorException

I’m using yii2-rbac-plus module. Everything seems to be working fine in the web app, but I just noticed this error in the console:

PHP Fatal error:  Class 'Yii\base\Exception' not found in /var/www/vhosts/.../vendor/johnitvn/yii2-rbac-plus/src/Module.php on line 74

PHP Fatal Error 'yii\base\ErrorException' with message 'Class 'Yii\base\Exception' not found'

in /var/www/vhosts/.../vendor/johnitvn/yii2-rbac-plus/src/Module.php:74

I’m not sure if this is a problem with the module or a configuration error on my end. I’ve tried adding

use yii\base\Exception;

to Module.php, but that has no effect.