Fatal error in PHP 7.1

In PHP 7.1, sv-gravity-forms-enhancer triggers a fatal error: Fatal error: Cannot use lexical variable $widget_class as a parameter name in path/to/plugins/sv-gravity-forms-enhancer/lib/core/widgets/widgets.php on line 128 Looks like this: add_action('widgets_init', function ($widget_class) use ($widget_class) { register_widget(get_class($widget_class)); }); This should be written as add_action('widgets_init', function () use ($widget_class) { register_widget(get_class($widget_class)); });