protected function addActivePluginsFilter()
    {
        // Add mu-plugins to active plugins
        add_filter('option_active_plugins', function ($plugins) {
            if ($this->isPluginsScreen()) {
                return $plugins;
            }

            if (empty($plugins)) {
                return $this->relativeFiles;
            }

            return array_unique(array_merge($plugins, $this->relativeFiles));
        });

        // Prevent active plugins to contain mu-plugins
        add_filter('pre_update_option_active_plugins', function ($plugins) {
            foreach ($plugins as $index => &$plugin) {
                if (strpos($plugin, $this->relativePath) === 0) {
                    unset($plugins[$index]);
                }
            }

            return array_unique(array_values($plugins)); // Fix array indices
        });
    }