diff --git a/test/H5BlockTestAttributes.c b/test/H5BlockTestAttributes.c
index dc7b60c..3483fe1 100644
--- a/test/H5BlockTestAttributes.c
+++ b/test/H5BlockTestAttributes.c
@@ -4,10 +4,7 @@
 #include "H5Part.h"
 #include "H5Block.h"
 #include "H5BlockTypes.h"
-#ifdef PARALLEL_IO
-#include <mpi.h>
-#else
-typedef int MPI_Comm;
+#ifndef PARALLEL_IO
 #ifndef MPI_COMM_WORLD
 #define MPI_COMM_WORLD 0
 #endif