diff --git a/examples/ex5f.f b/examples/ex5f.f
index 603da9ebc..293446945 100644
--- a/examples/ex5f.f
+++ b/examples/ex5f.f
@@ -75,8 +75,12 @@ c-----------------------------------------------------------------------
       call MPI_INIT(ierr)
       call MPI_COMM_RANK(MPI_COMM_WORLD, myid, ierr)
       call MPI_COMM_SIZE(MPI_COMM_WORLD, num_procs, ierr)
-c     for mpich, this is ok (LAM?)
-      mpi_comm = MPI_COMM_WORLD  
+
+c   Convert the Fortran MPI communicator to a C version that can be used in hypre.
+c   Uncomment the line below if you are using MPICH
+      mpi_comm = MPI_COMM_WORLD
+c   Uncomment the line below if you are using LAM-MPI
+c     call HYPRE_MPI_Comm_f2c(mpi_comm, MPI_COMM_WORLD, ierr)
 
 c   Default problem parameters
       n = 33