diff --git a/src/mpi/model/granted-time-window-mpi-interface.cc b/src/mpi/model/granted-time-window-mpi-interface.cc
index 4af05eeb7..bc79c31d1 100644
--- a/src/mpi/model/granted-time-window-mpi-interface.cc
+++ b/src/mpi/model/granted-time-window-mpi-interface.cc
@@ -52,7 +52,7 @@ NS_OBJECT_ENSURE_REGISTERED(GrantedTimeWindowMpiInterface);
 SentBuffer::SentBuffer()
 {
     m_buffer = nullptr;
-    m_request = nullptr;
+    m_request = MPI_REQUEST_NULL;
 }
 
 SentBuffer::~SentBuffer()
diff --git a/src/mpi/model/null-message-mpi-interface.cc b/src/mpi/model/null-message-mpi-interface.cc
index 7341d8800..ba990a135 100644
--- a/src/mpi/model/null-message-mpi-interface.cc
+++ b/src/mpi/model/null-message-mpi-interface.cc
@@ -97,7 +97,7 @@ const uint32_t NULL_MESSAGE_MAX_MPI_MSG_SIZE = 2000;
 NullMessageSentBuffer::NullMessageSentBuffer()
 {
     m_buffer = nullptr;
-    m_request = nullptr;
+    m_request = MPI_REQUEST_NULL;
 }
 
 NullMessageSentBuffer::~NullMessageSentBuffer()