diff --git a/bagua-core-internal/src/comm_ops/decentralized_full_precision_synchronous.rs b/bagua-core-internal/src/comm_ops/decentralized_full_precision_synchronous.rs
index 25f7ac7..7f10cad 100644
--- a/bagua-core-internal/src/comm_ops/decentralized_full_precision_synchronous.rs
+++ b/bagua-core-internal/src/comm_ops/decentralized_full_precision_synchronous.rs
@@ -87,11 +87,13 @@ impl CommOpTrait for DecentralizedFullPrecisionSynchronous {
                                 "you cannot use decentralized algorithm with average_all off when there are odd number of ranks, current n_ranks {}",
                                 c.nranks
                             );
-                            let comm_step = step / comm_interval;
+                            let comm_step = (step / comm_interval) as i64;
+                            let rank = c.rank as i64;
+                            let nranks = c.nranks as i64;
                             let peer_rank = if c.rank < c.nranks / 2 {
-                                ((comm_step + c.rank) % ((c.nranks + 1) / 2)) + (c.nranks / 2)
+                                ((comm_step + rank) % ((nranks + 1) / 2)) + (nranks / 2)
                             } else {
-                                (c.rank - (c.nranks / 2) - comm_step).rem_euclid(c.nranks / 2)
+                                (rank - (nranks / 2) - comm_step).rem_euclid(nranks / 2)
                             } as i32;
                             tracing::debug!("rank {} peer_rank {}", c.rank, peer_rank);
                             {