A computer-implemented method for enabling replication targets to reclaim unused storage space on thin-provisioned storage systems, at least a portion of the method being performed by a computing device comprising at least one processor, the method comprising: replicating, by a first replication agent on a replication source and a second replication agent on a replication target, data from the replication source to the replication target, wherein: a first thin-provisioned storage system provides a first allocated space (235) at the replication source; the data is stored to the first allocated space of the first thin-provisioned storage system; second thin-provisioned storage system provides a second allocated space (255) at the replication target; the second replication agent receives the data from the first replication agent via a block-based replication technique and stores the data to the second allocated space; identifying, by the first replication agent, an unused portion (239) of storage space within the first allocated space (235), transmitting, from the first replication agent to the second replication agent, information that identifies the unused portion (239) of storage space identifying, by the second replication agent, an unused portion (259) within the second allocated space (255) by receiving the information from the first replication agent; generating, by the second replication agent on the replication target, a reclamation request for reclaiming the unused storage space (259) within the second allocated space (255) from the second thin-provisioned storage system; and issuing, by the second replication agent, the reclamation request from the replication target to the second thin-provisioned storage system in order to reclaim the unused storage space (259) within the second allocated space (255) from the second thin-provisioned storage system. replicating, by a first replication agent on a replication source and a second replication agent on a replication target, data from the replication source to the replication target, wherein: a first thin-provisioned storage system provides a first allocated space (235) at the replication source; the data is stored to the first allocated space of the first thin-provisioned storage system; second thin-provisioned storage system provides a second allocated space (255) at the replication target; the second replication agent receives the data from the first replication agent via a block-based replication technique and stores the data to the second allocated space; a first thin-provisioned storage system provides a first allocated space (235) at the replication source; the data is stored to the first allocated space of the first thin-provisioned storage system; second thin-provisioned storage system provides a second allocated space (255) at the replication target; the second replication agent receives the data from the first replication agent via a block-based replication technique and stores the data to the second allocated space; identifying, by the first replication agent, an unused portion (239) of storage space within the first allocated space (235), transmitting, from the first replication agent to the second replication agent, information that identifies the unused portion (239) of storage space identifying, by the second replication agent, an unused portion (259) within the second allocated space (255) by receiving the information from the first replication agent; generating, by the second replication agent on the replication target, a reclamation request for reclaiming the unused storage space (259) within the second allocated space (255) from the second thin-provisioned storage system; and issuing, by the second replication agent, the reclamation request from the replication target to the second thin-provisioned storage system in order to reclaim the unused storage space (259) within the second allocated space (255) from the second thin-provisioned storage system.