diff --git a/ompi/mca/osc/rdma/osc_rdma_accumulate.c b/ompi/mca/osc/rdma/osc_rdma_accumulate.c
index ef62b24e46..65617bab7b 100644
--- a/ompi/mca/osc/rdma/osc_rdma_accumulate.c
+++ b/ompi/mca/osc/rdma/osc_rdma_accumulate.c
@@ -976,7 +976,7 @@ int ompi_osc_rdma_compare_and_swap (const void *origin_addr, const void *compare
         return OMPI_ERR_RMA_SYNC;
     }
 
-    ret = osc_rdma_get_remote_segment (module, peer, target_disp, 8, &target_address, &target_handle);
+    ret = osc_rdma_get_remote_segment (module, peer, target_disp, dt->super.size, &target_address, &target_handle);
     if (OPAL_UNLIKELY(OPAL_SUCCESS != ret)) {
         return ret;
     }