diff --git a/Grid/communicator/Communicator_mpi3.cc b/Grid/communicator/Communicator_mpi3.cc
index ef9a2c965..e352db21d 100644
--- a/Grid/communicator/Communicator_mpi3.cc
+++ b/Grid/communicator/Communicator_mpi3.cc
@@ -191,6 +191,7 @@ CartesianCommunicator::CartesianCommunicator(const Coordinate &processors,const
   // Set up from the new split communicator
   //////////////////////////////////////////////////////////////////////////////////////////////////////
   InitFromMPICommunicator(processors,comm_split);
+  _shm_processors = shm_processors;
 
   //////////////////////////////////////////////////////////////////////////////////////////////////////
   // Take the right SHM buffers