Changelog says * PHPC-2637: Update to libmongoc 1.30.6 by @alcaeus in https://github.com/mongodb/mongo-php-driver/pull/1882 But archive content is the same than 2.1.2, so 1.30.5 See https://github.com/mongodb/mongo-php-driver/blob/2.1.3/src/LIBMONGOC_VERSION_CURRENT So 2.1.3 is an "no change" version