Yeah, didn't know if I could assume developers working with bundler. Had the other version before but thought it would be nice to have a single expression handle the detection. Do you have any objections to a constant that's defined somewhere in `helper.rb`? BTW: [bundler's check](https://github.com/bundler/bundler/blob/6423da7150b880a68d8378c200de11f8c0a4b070/lib/bundler/constants.rb#L2) is broader