Maintaining a synchronous replication relationship between two or more storage systems, including: receiving, by at least one of a plurality of storage systems across which a dataset will be synchronously replicated, timing information for at least one of the plurality of storage systems; and establishing, based on the timing information, a synchronous replication lease describing a period of time during which the synchronous replication relationship is valid, wherein a request to modify the dataset may only be acknowledged after a copy of the dataset has been modified on each of the storage systems.