diff --git a/source/adios2/helper/adiosMPIFunctions.tcc b/source/adios2/helper/adiosMPIFunctions.tcc
index f2f9777597..fd793d7f62 100644
--- a/source/adios2/helper/adiosMPIFunctions.tcc
+++ b/source/adios2/helper/adiosMPIFunctions.tcc
@@ -259,31 +259,35 @@ std::vector<MPI_Request> Isend64<char>(const char *buffer, const size_t count,
                                        int dest, int tag, MPI_Comm mpiComm,
                                        const std::string &hint)
 {
-    const size_t batches = count / DefaultMaxFileBatchSize;
-    std::vector<MPI_Request> requests(batches + 1);
 
-    if (batches > 1)
+    std::vector<MPI_Request> requests(1);
+
+    if (count > DefaultMaxFileBatchSize)
     {
+        const size_t batches = count / DefaultMaxFileBatchSize;
+        requests.resize(batches);
+
         size_t position = 0;
         for (size_t b = 0; b < batches; ++b)
         {
             int batchSize = static_cast<int>(DefaultMaxFileBatchSize);
-            CheckMPIReturn(
-                MPI_Isend(const_cast<char *>(buffer + position), batchSize,
-                          MPI_CHAR, dest, tag, mpiComm, &requests[b]),
-                "in call to Isend64 batch " + std::to_string(b) + "/" +
-                    std::to_string(batches) + " " + hint + "\n");
+            CheckMPIReturn(MPI_Isend(const_cast<char *>(buffer + position),
+                                     batchSize, MPI_CHAR, dest, tag, mpiComm,
+                                     &requests[b]),
+                           "in call to Isend64 batch " + std::to_string(b) +
+                               " " + hint + "\n");
 
             position += DefaultMaxFileBatchSize;
         }
         const size_t remainder = count % DefaultMaxFileBatchSize;
         if (remainder > 0)
         {
+            requests.resize(batches + 1);
             int batchSize = static_cast<int>(remainder);
             CheckMPIReturn(MPI_Isend(const_cast<char *>(buffer + position),
                                      batchSize, MPI_CHAR, dest, tag, mpiComm,
-                                     &requests[batches - 1]),
-                           "in call to Isend64 last batch " + hint + "\n");
+                                     &requests[batches]),
+                           "in call to Isend64 remainder batch " + hint + "\n");
         }
     }
     else
@@ -302,18 +306,12 @@ std::vector<MPI_Request> Irecv64<char>(char *buffer, const size_t count,
                                        int source, int tag, MPI_Comm mpiComm,
                                        const std::string &hint)
 {
-    const size_t batches = count / DefaultMaxFileBatchSize;
-    std::vector<MPI_Request> requests(batches + 1);
+    std::vector<MPI_Request> requests(1);
 
-    if (requests.size() != batches + 1)
-    {
-        throw std::runtime_error(
-            "ERROR: number of Irecv requests doesn't match number of batches = "
-            "count/DefaultMaxFileBatchSize\n");
-    }
-
-    if (batches > 1)
+    if (count > DefaultMaxFileBatchSize)
     {
+        const size_t batches = count / DefaultMaxFileBatchSize;
+        requests.resize(batches);
         size_t position = 0;
         for (size_t b = 0; b < batches; ++b)
         {
@@ -321,19 +319,19 @@ std::vector<MPI_Request> Irecv64<char>(char *buffer, const size_t count,
             CheckMPIReturn(MPI_Irecv(buffer + position, batchSize, MPI_CHAR,
                                      source, tag, mpiComm, &requests[b]),
                            "in call to Irecv64 batch " + std::to_string(b) +
-                               "/" + std::to_string(batches) + " " + hint +
-                               "\n");
+                               " " + hint + "\n");
 
             position += DefaultMaxFileBatchSize;
         }
+
         const size_t remainder = count % DefaultMaxFileBatchSize;
         if (remainder > 0)
         {
+            requests.resize(batches + 1);
             int batchSize = static_cast<int>(remainder);
             CheckMPIReturn(MPI_Irecv(buffer + position, batchSize, MPI_CHAR,
-                                     source, tag, mpiComm,
-                                     &requests[batches - 1]),
-                           "in call to Irecv64 last batch " + hint + "\n");
+                                     source, tag, mpiComm, &requests[batches]),
+                           "in call to Irecv64 remainder batch " + hint + "\n");
         }
     }
     else
diff --git a/source/adios2/toolkit/aggregator/mpi/MPIChain.cpp b/source/adios2/toolkit/aggregator/mpi/MPIChain.cpp
index af26b671ee..7ea74670ae 100644
--- a/source/adios2/toolkit/aggregator/mpi/MPIChain.cpp
+++ b/source/adios2/toolkit/aggregator/mpi/MPIChain.cpp
@@ -7,7 +7,6 @@
  *  Created on: Feb 21, 2018
  *      Author: William F Godoy godoywf@ornl.gov
  */
-
 #include "MPIChain.h"
 
 #include "adios2/ADIOSMPI.h"
@@ -58,13 +57,19 @@ std::vector<std::vector<MPI_Request>> MPIChain::IExchange(BufferSTL &bufferSTL,
                                ", aggregation Isend size at iteration " +
                                    std::to_string(step) + "\n");
 
-        const std::vector<MPI_Request> requestsISend64 = helper::Isend64(
-            sendBuffer.m_Buffer.data(), sendBuffer.m_Position, m_Rank - 1, 1,
-            m_Comm,
-            ", aggregation Isend64 data at iteration " + std::to_string(step));
+        // only send data if buffer larger than 0
+        if (sendBuffer.m_Position > 0)
+        {
+
+            const std::vector<MPI_Request> requestsISend64 =
+                helper::Isend64(sendBuffer.m_Buffer.data(),
+                                sendBuffer.m_Position, m_Rank - 1, 1, m_Comm,
+                                ", aggregation Isend64 data at iteration " +
+                                    std::to_string(step));
 
-        requests[0].insert(requests[0].end(), requestsISend64.begin(),
-                           requestsISend64.end());
+            requests[0].insert(requests[0].end(), requestsISend64.begin(),
+                               requestsISend64.end());
+        }
     }
     // receive size, resize receiving buffer and receive data
     if (receiver)
@@ -89,10 +94,15 @@ std::vector<std::vector<MPI_Request>> MPIChain::IExchange(BufferSTL &bufferSTL,
             "in aggregation, when resizing receiving buffer to size " +
                 std::to_string(bufferSize));
 
-        requests[1] = helper::Irecv64(
-            receiveBuffer.m_Buffer.data(), receiveBuffer.m_Position, m_Rank + 1,
-            1, m_Comm,
-            ", aggregation Irecv64 data at iteration " + std::to_string(step));
+        // only receive data if buffer is larger than 0
+        if (bufferSize > 0)
+        {
+            requests[1] =
+                helper::Irecv64(receiveBuffer.m_Buffer.data(),
+                                receiveBuffer.m_Position, m_Rank + 1, 1, m_Comm,
+                                ", aggregation Irecv64 data at iteration " +
+                                    std::to_string(step));
+        }
     }
 
     return requests;