load_plugin_textdomain driving me insane!

add_action('init', 'kfuk_widgets_load_translations');
function kfuk_widgets_load_translations() {
	load_plugin_textdomain('kfukwidgets', false, dirname( plugin_basename( __FILE__ ) ) . '/languages/');
}

class kfuk_gift_widget extends \WP_Widget {
	function __construct() {
// snip:d for brevity
	}

	function widget($args, $instance) {
		// output
		__("this is a test", "kfukwidgets");
	}

	function update($new_instance, $old_instance) {
// snip:d for brevity
	}

	function form($instance) {
// snip:d for brevity
	}
}

I have created a kfukwidgets-default.pot file, with POEdit, I then duplicated it, renamed it to kfukwidgets-sv_SE.po, I then translated the string in POEdit, which I then saved and it generated a kfukwidgets-sv_SE.mo file.

But the translation won’t work even if get_locale() reports the very same locale I have defined in the file name.