Save a few bytes when checking the existence of module

Say we are creating a library and want to export our APIs to the consumers. In order to support the CommonJS module, we use the following check:
if (typeof module !== 'undefined') {
module.exports = ourFunction;
However, it can be shorten and saved a few bytes when being minified:
if (typeof module < 'u') {
// ...
I saw that trick when looking at the Preact's source.