diff --git a/src/USER-CUDA/comm_cuda.cpp b/src/USER-CUDA/comm_cuda.cpp
index 50ff0916e7..9df27080dc 100644
--- a/src/USER-CUDA/comm_cuda.cpp
+++ b/src/USER-CUDA/comm_cuda.cpp
@@ -638,15 +638,17 @@ void CommCuda::forward_comm_pair(Pair *pair)
   MPI_Request request;
   MPI_Status status;
 
+  int nsize = pair->comm_forward;
+
   for (iswap = 0; iswap < nswap; iswap++) {
 
     // pack buffer
 
-    n = pair->pack_comm(sendnum[iswap],&iswap,
-                        buf_send,pbc_flag[iswap],pbc[iswap]);
-        int nrecv = recvnum[iswap]*n;
+    n = pair->pack_forward_comm(sendnum[iswap],&iswap,
+                                buf_send,pbc_flag[iswap],pbc[iswap]);
+        int nrecv = recvnum[iswap]*nsize;
         if(nrecv<0) nrecv=-(nrecv+1)/2;
-        int nsend = sendnum[iswap]*n;
+        int nsend = n;
         if(nsend<0) nsend=-(nsend+1)/2;
 
     // exchange with another proc
@@ -662,7 +664,7 @@ void CommCuda::forward_comm_pair(Pair *pair)
 
     // unpack buffer
 
-    pair->unpack_comm(recvnum[iswap],firstrecv[iswap],buf);
+    pair->unpack_forward_comm(recvnum[iswap],firstrecv[iswap],buf);
   }
 }