diff --git a/configure.ac b/configure.ac
index fb552765e6..326eea8872 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1278,7 +1278,7 @@ if test "$MPI_OFFSET_TYPE" = "not found"; then
 	AC_MSG_WARN([*** Unable to find the right definition for MPI_Offset])
 	AC_MSG_ERROR([Cannot continue])
 fi
-AC_DEFINE_UNQUOTED(MPI_Offset, $MPI_OFFSET_TYPE, [Type of MPI_Offset])
+AC_DEFINE_UNQUOTED(OMPI_MPI_OFFSET_TYPE, $MPI_OFFSET_TYPE, [Type of MPI_Offset -- has to be defined here and typedef'ed later because mpi.h does not get AC SUBST's])
 
 #
 # If we haven't already, figure out an MPI datatype that corresponds
diff --git a/include/mpi.h.in b/include/mpi.h.in
index 847aeace4a..d0bb42479f 100644
--- a/include/mpi.h.in
+++ b/include/mpi.h.in
@@ -67,8 +67,8 @@
 /* The size of a `int', as computed by sizeof. */
 #undef SIZEOF_INT
 
-/* Type of MPI_Offset */
-#undef MPI_Offset
+/* Type of MPI_Offset -- has to be defined here and typedef'ed later because mpi.h does not get AC SUBST's */
+#undef OMPI_MPI_OFFSET_TYPE
 
 /* Whether we want MPI cxx support or not */
 #undef OMPI_WANT_CXX_BINDINGS
@@ -140,6 +140,7 @@ extern "C" {
  * Typedefs
  */
 typedef long MPI_Aint;
+typedef OMPI_MPI_OFFSET_TYPE MPI_Offset;
 typedef struct ompi_communicator_t *MPI_Comm;
 typedef struct ompi_datatype_t *MPI_Datatype;
 typedef struct ompi_errhandler_t *MPI_Errhandler;