Undefined variable: module in styles_style_features_export

With the recently committed code that adds the features integration, I'm getting this warning message:

Notice: Undefined variable: module in styles_style_features_export() (line 29 of styles/includes/styles.features.inc).

Changing

$export['dependencies'][$module] = $style['module'];

to

$export['dependencies'][$module_name] = $style['module'];

removed the warning message for me, though I'm not 100% sure this is the appropriate syntax for the features dependencies code.