Discussing things with @michaelmosmann, we were misusing the feature-aware version support and it will stop working with Embedded Mongo 3.4.x. Rather than getting stuck on an old version of Embedded Mongo, at least while a deprecation period elapses, we will remove support for spring.mongodb.embedded.features in 2.7.x. For advanced configuration, instead of using features to manipulate the command line that's used to launch Mongo, users should define their own MongodConfig bean.